:-NRLF 


Eb    D7M 


OGRESS!VE 


FURNACE 
HEATING 


PROGRESSIVE 
FURNACE  HEATING 

By  ALFRED  G.  KING 


A  PRACTICAL  MANUAL  OF  DESIGNING,  ESTIMATING 

AND  INSTALLING  MODERN  SYSTEMS  FOR 

HEATING  AND  VENTILATING 

BUILDINGS  WITH 

WARM  AIR 


Supplemented  by 

A  COMPLETE  TREATISE  ON  THE  CONSTRUCTION  AND 
PATTERNS  OF  FURNACE   FITTINGS 

By  WILLIAM  NEUBECKER 


NEW  YORK 
SHEET  METAL  PUBLICATION  COMPANY 

1914 


,  t 


Copyright  1914 

BY 
The  Sheet  Metal  Publication  Company 


TABLE  OF  CONTENTS  3 

CHAPTER  I. 

The  Chimney  Flue — Character  and  Size  of  Flue — Area  and 
Height  Required — How  Correct  Tests  are  Made — Loca- 
tion of  the  Chimney — Common  Sources  of  Trouble — 
Chimney  Flue  Troubles. 

CHAPTER  II. 

The  Furnace — History  of  the  Furnace — Character  and  Size 
of  the  Furnace — Furnace  Casing  and  Top — Location  of 
Furnace — Methods  of  Setting — The  Cold  Air  Supply — Size 
of  Furnace  Required. 

CHAPTER  III. 

Pipe,  Fittings  and  Registers — Size  and  Location  of  Reg- 
isters— Table  of  Sizes  Required. 

CHAPTER  IV. 

Installation  of  the  Furnace — Tabulated  Estimate — How  to 
Determine  Size  of  Furnace  Required — Sizes  of  Pipes  and 
Risers. 

CHAPTER  V. 

Trunk  Line  and  Fan-Blast  Hot  Air  Heating — Methods  of 
Trunk  Line  Piping — Sizes  of  Piping  for  Trunk  Lines — 
Fan-Blast  Heating — Methods  of  Installation — A  Typical 
Installation  of  Fan-Blast  Heating. 

CHAPTER  VI. 

Estimating  Furnace  Work — How  to  Estimate — An  Illustrated 
Example — Form  of  Estimate  Sheet — Determining  Cost. 

CHAPTER  VII. 

Intelligent  Application  of  Heating  Rules — Heat  Losses  are 
the  Basis  of  Sizes  Required — An  Automatic  Air  Damper. 

CHAPTER  VIII. 

Practical  Methods  of  Construction — A  Detailed  Illustration- 
Superior  Work  Brings  Best  Results — School  House 
Warming  and  Ventilation — An  Example  of  Fan-Blast 
Heating  for  Schools — A  Trunk  Line  Installation. 

CHAPTER  IX. 

What  Constitutes  Good  Furnace  Work— Dust  Discharge— 
The  Casing — The  Furnace  Top — The  Piping — Concern- 
ing Bends — Heating  Surface — Added  Cost  of  Hard  Firing 
— An  Example  of  High  Class  Work. 


387478 


4  TABLE  OF  CONTENTS 

CHAPTER  X. 

Ventilation — The  Need  of  Pure  Air — Amount  of  Fresh  Air 
Required  —  Methods  of  Ventilating  —  A  Ventilating 
Chimney. 

CHAPTER  XL 

Ventilation  by  the  Use  of  Propeller  Fan — Methods  Em- 
ployed— Volume  of  Air  Moved  by  Fans  of  Various 
Sizes — Efficiency  of  Exhaust  Fans — Tables  of  Speed  and 
Capacity. 

CHAPTER  XII. 

Humidity  and  the  Value  of  Air  Moistening — Reduction  of 
Fuel — Results  of  Investigation — Coke  Air  Moistener — 
The  Herr  Humidizer — The  Water  Pan — The  Hygro- 
meter. 

CHAPTER  XIII. 

Recirculation  of  Air  in  Furnace  Heating — Quality  of  Air — 
Air  Outlet  Necessary — Heating  Windward  Side — Op- 
position to  the  Method — Obtaining  Best  Results — Con- 
necting Duct. 

CHAPTER  XIV. 

Auxiliary  Heating  from  Furnaces — Computing  Size  of  Radi- 
ator— Heating  Surface  Required — Installing  the  Ap- 
paratus. 

CHAPTER  XV. 

Temperature  Regulation  and  Fuel  Saving  Devices — Fuel 
Saving  Appliances — Electric  Regulators — Non-Electric 
Regulators — How  to  Sell  Thermostats — The  Cost  of  Heat 
Regulation — How  to  Attach  Thermostats — Automatic 
Draft  Regulators — Operation  and  Installation — Chain 
Control  of  Drafts. 

CHAPTER  XVI. 

Fuel — Its  Chemical  Components  and  Combustion — Classifi- 
cation of  Coal — Methods  of  Burning  Coal — Coal:  The 
Universal  Fuel. 

CHAPTER  XVII. 

Cement  Construction  for  Furnace  Men — Concrete  Mixtures — • 
Mixing  Concrete — Tools  Required — Determining  Qanti- 
ties — Methods  Employed. 


TABLE  OF  CONTENTS  5 

CONSTRUCTION  AND  PATTERNS 
OF  FURNACE  FITTINGS 

CHAPTER  XVIII. 

Remarks — Conical    Bonnets    or    Hoods — Furnace    Casings — 
Various  Styles  of  Collars — Patterns  for  Collar  on  Pitched 
Bonnet — Patterns  for  Collar  on  Straight  Bonnet — Fasten- 
ing   the    Collars    to    the    Bonnet — Elbows — Applying    the 
Rule — Elbows    Less   Than    Right   Angles — Seaming   the 
Circular  Joints — Oval  Elbows — Developing  the  Patterns 
for  a  Reducing  Elbow — T  Joint  Between  Pipes  of  Un- 
equal Diameters  at  an  Angle — Construction  of   Riveted 
Joints   in  Tees — Construction  of  Cold  Air  Shoes — Pattern 
for  Shoe  Connecting  to  Center  of  Furnace — Patterns  for 
Shoe   Connecting  to   One  Side  of  Furnace — Frictionless 
Cold  Air  Duct  Elbows— Seaming  Cold  Air  Duct  Elbows 
— Developing  and  Constructing  Floor  Register  Boxes — 
Rule   for   Determining  the   Size   of  the   Register   Box — 
Table  of  Areas  of  Round  Pipes  and  Registers — Pattern 
for  Floor  Register  Box  in  One  Piece — Pattern  for  Floor 
Register  in  Four  Pieces — Quick  Method  of  Joining  Collar 
to    Register    Box — Two    Other    Methods    of    Connecting 
Register    Boxes — Construction    of    Combination    Header 
and  Register  Box — Boots  or  Wall  Pipe  Starters — Devel- 
oping the   Pattern   for  a   Round   to   "Oval"   Frictionless 
Starter — Various   Styles  of  Frictionless   Starters — Offset 
Boot — Developing  the  Patterns — Wall  Pipes  or  Risers — 
Covering  Single  Wall  Pipes  With  Paper — Double  Wall 
Pipes — Metal  Flues  in  Brick  Walls — The  Various  Fittings 
Used  in  Furnace  Piping — Compound  Wall  Pipe  Offsets — 
Patterns  for  a  Double  Offset — Fittings  for  Truck   Line 
Heating  Systems — Short  Rule  for  Reducing  Joint — De- 
'termining  the  Unknown   Diameter  of  the   Main   Pipe — 
Pattern    for   a    Fork    of    Equal    Prongs    in   Trunk    Line 
System — Determining  the  Unknown  Diameter  in  an  Un- 
equal   Two    Pronged    Fork — Placing    the    Half    Profiles 
Previous     to     Developing    the     Patterns — Three     Equal 
Pronged  Fork — Method  of  Drawing  Three  Pronged  Fork 
so  That  the  Patterns  for  One  Will  Answer  for  All  Times 
— Unequal  Three  Pronged  Fork — Finding  the  True  Sec- 
tions and  Placing  the  Two  Profiles  in  an  Unequal  Three 
Pronged   Fork — Finding  True  Angles  in  Cold  Air  Duct 
Elbows — Method   Employed   When   Developing   the    El- 
bow Patterns — True  Angles  in  Warm  Air  Elbows — Find- 
ing True  Angles  With  Line  and  Bevel. 


6  TABLE  OF  CONTENTS 

CHAPTER  XIX. 

Rules,  Tables  and  Useful  Information — Weights  of  Steel- 
Gauges  and  Weights  of  Black  Sheets — Galvanized 
Sheets — Weights  of  Galvanized  Pipe  and  Elbows — Sheet 
Copper— Sheet  Zinc— Net  Weight  Box  Tin  Plates— Stock 
Sizes  Tin  Pipe — Roofing — Tin  Tables — Cost  of  Stand- 
ing Seam  Tin  Roofing — Weight,  Strength  and  Size  of 
Wire — Wire  Gauge — Dimensions  of  Registers — Size  of 
Registers — Weights  and  Measures — Common  Fractions 
and  Decimals — Millimeters  and  Decimals — Gallons  in 
Rectangular  Tanks — Gallons  in  Round  Tanks — Barrel 
Capacity  of  Tanks  and  Cisterns — Areas  and  Circumfer- 
ences of  Circles — Rules  Relative  to  the  Circle — Melting 
Points  of  Metals — Boiling  Points  of  Fluids — Horse  Power 
of  Belting  Cubical  Contents  of  Rooms, 

CHAPTER  XX. 

Receipts  and  Miscellaneous  Information — To  Clean  Brass — 
To  Clean  Zinc — To  Clean  Water  Front  of  Rust — To  Re- 
move Lime  Deposit  From  Water  Front — Government 
Receipt  for  Cleaning  Brass — To  prevent  Rusting  of  Iron 
and  Steel — To  Prevent  Polished  Iron  From  Rusting— 
To  Clean  Zinc — How  to  Clean  Steel  Tapes — To  Paint 
Galvanized  Iron — To  Keep  Plaster  of  Paris  From  Setting 
Too  Quickly — To  Solder  Galvanized  Iron — A  Flux  for 
Tin  Roofing — Fluxes  for  Various  Metals — To  Keep 
Soldering  Coppers  Hot — A  Good  Soldering  Acid — A  Non- 
Corrosive  Soldering  Paste. — Waterproof  Glue — How  to 
Make  Putty — Fireproof  Cement  for  Furnaces — Rust 
Joints — Friction  of  Water  in  Passing  Through  Pipes — 
Heating  Capacity  of  Stove  and  Furnace  Coils. 

Index     I — Furnace  Heating    Page  269 

Index  II — Furnace  Fittings    Page  276 


INTRODUCTORY. 


A  large  part  of  the  following  text  is  compiled  from  a 
series  of  articles  written  for  SHEET  METAL. 

To  this  text  new  material  has  been  added,  and  the 
original  work  has  been  edited,  revised  and  extended  to  make 
the  book  a  useful,  practical  and  instructive  treatise  on  the 
subject  of  furnace  heating. 

Few  of  those  at  present  engaged  in  the  installation  of 
the  warm  air  furnace  realize  the  possibilities  of  warm  air 
heating. 

The  trouble  has  been  with  the  many  furnace  dealers  who 
have  failed  to  be  honest  with  themselves.  Instead  of  adopt- 
ing and  following  the  motto  "onward  and  upward"  and  work- 
ing to  uplift  and  develop  the  science  of  warm  air  heating 
(for  it  is  a  science)  their  rule  seemingly  has  been  "downward 
and  cheapward,"  if  the  use  of  such  'an  expression  is  permis- 
sible. They  have  thus  done  much  to  discredit  this  method 
of  heating  with  the  house  owner  and  even  with  physicians 
and  heating  and  ventilating  engineers,  who,  of  course,  regard 
it  strictly  from  the  standpoint  of  efficiency  and  economy.  It 
has  not  been  the  furnace  (as  it  should  be  constructed)  or  the 
method  of  furnace  heating  (as  the  work  should  be  installed), 
but  rather  the  cheap,  claptrap  methods  of  furnace  building 
and  installation  which  have  in  a  measure  served  to  bring 
discredit  on  the  dealer  and  manufacturer  alike. 

It  is  one  of  the  peculiar  laws  of  progression  that  while  it 
often  takes  years  of  constant  labor,  energy  and  attention  to 
work  out  the  salvation  of  a  business  or  a  principle,  the  repu- 
tation and  standing  thus  attained  may  be  throttled  as  it  were, 
over  night,  or,  putting  this  thought  into  a  concrete  form 
bearing  on  our  present  discussion,  one  good  job  of  heating 
will  sell  two  or  three  other  jobs  and  one  poor  job  will  result 
in  the  loss  of  ten  others. 

The  indications  point  to  a  much  more  general  popularity  for 
the  warm  air  furnace  and  an  encouraging  view  obtains  for  a 
general  expansion  of  the  industry,  hence  every  precaution  should 
be  taken  to  safeguard  its  growth. 


8  INTRODUCTORY 

Cheap  competition  work,  the  feverish  endeavor  to  beat 
out  a  competitor  by  lowering  prices  to  ridiculous  figures,  the 
use  of  inferior  furnaces  and  materials,  the  catering  to  so- 
called  "operation  work"  where  from  ten  to  one  hundred  or 
more  houses  are  fitted  with  heating  apparatus  and  where 
the  saving  of  from  five  to  ten  dollars  per  house  is  looked  upon 
as  being  a  good  stroke  of  business — these  are  some  of  the 
causes  of  condemnation  brought  about  by  the  contractor. 

Cheap  furnace  construction,  the  use  of  inferior  materials, 
the  gross  overrating  of  capacities  and  the  sale  of  furnaces  to 
dealers  who  are  ignorant  of  the  principles  of  heating  have 
been  the  manufacturer's  contribution  to  the  unsatisfactory 
conditions  which  long  existed  in  this  field.  In  actual  results 
attained,  this  practice  of  cheap  work  is  demoralizing. 

The  inability  to  properly  warm  a  room  may  be  due  to 
faulty  construction,  an  improper  location  of  stack  or  register, 
lack  of  capacity  at  the  heart  of  the  system — the  furnace — or 
any  one  of  a  dozen  other  causes.  The  dissemination  of  gas 
and  dust  into  the  rooms,  the  excessive  consumption  of  fuel, 
the  dry,  oppressive  atmosphere  present  in  the  heated  dwell- 
ing— these  and  other  marks  of  failure  or  unhealthful  condi- 
tions may  be  remedied  by  the  application  of  common  sense 
methods. 

ALFRED  G.  KING. 

January,  1914. 


Progressive  Furnace  Heating 

CHAPTER   I 
THE    CHIMNEY    FLUE 

The  preparation  for  the  installation  of  a  furnace  heating 
system  should  begin  with  the  foundation  of  the  building  to 
be  heated  if  the  best  results  are  to  be  expected  from  the 
operation  of  the  apparatus.  The  erection  of  a  chimney  flue 
of  proper  size  placed  in  the  proper  location  is  one  of  the 
principal  points  of  building  construction,  making,  as  it  does, 
for  efficiency  and  economy  in  so  far  as  the  heating  apparatus 
is  concerned.  Chimneys  defective  in  construction  and  those 
located  in  isolated  or  inaccessible  parts  cause  a  large  share 
of  the  failures  of  furnaces  to  work  properly.  It  therefore 
behooves  the  installer  to  look  well  to  the  character  and 
position  of  the  chimney. 

The  human  body  has  been  likened  to  a  furnace,  and  it 
is  indeed  a  heating  apparatus  of  the  most  delicate  and  intri- 
cate kind. 

The  mouth  and  nose  may  be  called  the  draft  door  and 
chimney  of  the  human  furnace,  and  should  the  nose  become 
clogged  and  the  throat  filled  with  matter,  the  fire  of  the 
body  is  suffocated  for  want  of  oxygen,  the  furnace  ceases  to 
work  and  the  body  dies. 

As  the  ability  of  the  human  furnace  to  breathe  properly 
is  necessary,  just  so  is  the  ability  of  the  hot  air  furnace  to 
breathe  properly  a  necessity,  if  the  full  measure  of  work  and 
activity  of  either  are  to  be  maintained. 

The  question  of  the  chimney  for  use  with  a  furnace  is 
so  important  that  it  is  the  first  thing  to  be  examined  when 
planning  to  install  a  heating  apparatus. 

Character  and  Size  of  Flue. 

It  is  a  well  established  fact  that  the  draft  in  a  chimney 
flue  is  spiral  —  that,  as  the  air  in  the  flue  is  heated  and 
expanded  by  the  hot  gases  and  products  of  combustion,  it 
rises  in  the  flue,  ascending  with  a  spiral  motion  and  increas- 
ing in  velocity  according  to  the  amount  of  air  passed  through 
the  grate  of  the  furnace.  In  other  words,  the  greater  the 
opening  resulting  from  the  setting  of  the  draft  door,  the 
more  active  will  be  the  combustion  of  the  fuel,  and,  if  the 


10 


FLUES  AND  CHIMNEYS 


chimney  be  of  the  proper  height  and  area,  the  greater  the 
velocity  of  the  draft. 

It  is  by  reason  of  the  fact  that  the  draft  is  spiral  that 
a  round  smooth  flue  is  preferable  to  all  other  styles  of  chim- 
ney construction.  Next  in  value  is  the  square  flue,  or  one 
as  nearly  square  as  conditions  of  construction  will  permit. 
Fig.  i  illustrates  a  round  tile  flue  encased  in  brick,  represent- 
ing the  best  possible  type  of  construction.  Should  we  suppose 
the  tile  to  be  12  inches  inside  diameter,  the  chimney  would 
have  an  area  of  113  square  inches. 


Fig.  i — Brick  Chimney  with  Round  Tile  Flue. 

Fig.  2  illustrates  a  square  tile-lined  flue,  encased  in  brick. 
Assuming  the  width  to  be  12  inches,  same  as  the  diameter 
in  Fig.  i,  this  flue  would  have  an  area  of  144  square  inches, 
or  31  square  inches  of  area  more  than  the  round  flue,  and  yet 
the  latter  will  do  the  same  work  equally  well,  if  not  better. 

Builders,  and  frequently  owners,  complain  that  a  tile- 
lined  specially  built  flue  is  costly.  It  is  costly — not  to  build 
it.  It  is  a  continual  fuel  saver,  and  by  saving  from  one  to 
three  tons  of  fuel  yearly  will  soon  pay  for  the  increased  cost. 
Very  few  investments  will  afford  the  same  return  in  dividends 
as  will  the  money  expended  for  a  good  chimney  flue. 

The  depth  of  a  rectangular  flue  should  never  be  less  than 
the  diameter  of  the  smoke  pipe  which  enters  it. 

Do  not  be  deceived  into  thinking  that  a  flue  full  large 
for  the  work  means  a  corresponding  increase  in  the  consump- 
tion of  fuel,  as  tests  have  demonstrated  that  a  poor  flue  will 
frequently  consume  more  fuel  than  one  of  proper  size,  and  at 
the  same  time  produce  less  results  in  heat  units  delivered  to 
the  rooms  to  be  warmed.  When  fuel  is  burning  under  the 
former  condition  there  seems  to  be  no  life  to  the  combustion. 


FLUES  AND  CHIMNEYS 


ii 


The  fire  is  a  dull  red,  the  smoke  pipe  is  cool,  and  the  tem- 
perature of  the  gases  in  the  flue  is  so  low  that  proper  condi- 
tions of  draft  are  out  of  the  question. 

It  is  all  important  that  the  furnace  dealer  should  post 
himself  thoroughly  on  chimney  construction.  It  is  the  first 
and  most  necessary  study  in  qualifying  as  a  heating  expert. 
A  furnace  man  has  no  business  to  install  furnaces  when  he 
is  not  capable  of  advising  as  to  proper  chimney  construction. 

Beware  of  long  narrow  flues,  because  but  a  small  portion 
of  the  area  of  such  can  be  counted  upon  to  prove  effective. 


Fig.  2 — Brick  Chimney  with  Square  Tile  Flue. 


For  example,  a  flue  4  by  16  inches  may  be  rightly  considered 
as  being  no  more  effective  than  a  6  inch  round  pipe.  The 
dead  air  area  in  the  ends  of  this  rectangular  flue  is  of  no  value 
whatever.  On  the  contrary,  it  is  frequently  a  hindrance, 
owing  to  friction  and  down-draft  likely  to  prevail.  Fig.  3 
illustrates  this  fact,  the  shaded  portion  of  the  flue  representing 
its  effective  area.  If  a  flue  be  built  of  brick  without  a  tile 
lining,  it  should  be  pointed  smooth  on  the  inside,  not  plastered, 
as  the  plaster  lining  will  loosen  and  drop  down  in  patches, 
frequently  taking  a  quantity  from  between  the  bricks,  thereby 
loosening  them  and  damaging  the  chimney. 

By  adding  to  the  height  of  a  chimney  the  velocity  of  the 
flue  may  be  increased  at  small  expense.  The  area,  however, 
cannot  be  well  increased  without  considerable  cost,  and  it 
should  therefore  be  great  enough  from  the  start  to  fulfill  all 
possible  requirements. 

All  chimneys  should  be  built  straight  from  bottom 
to  top  without  offsets  of  any  character.  Where  an  abrupt 


12 


FLUES  AND  CHIMNEYS 


offset  is  made  in  a  chimney  a  place  is  provided  upon  which 
soot  will  lodge  and  after  a  time  clog  the  flue  opening,  as 
shown  by  Fig.  4.  This  is  a  common  cause  of  the  failure  of 
many  flues  in  city  houses  where  a  block  is  built  up  solid 
with  openings  or  area-ways  left  for  passage  between  houses, 
the  second  floor  being  set  out  over  the  area-way.  Chimneys 
are  often  offsetted  three  or  four  feet  in  this  style  of  building 
construction,  and  as  a  result  prove  a  great  detriment  to  the 
successful  working  of  the  furnace, 


Fig.  3 — Rectangular  Flue  Showing  Effective  Area. 


A  chimney  to  be  effective  at  all  times  and  under  all  con- 
ditions of  wind  and  weather,  should  extend  at  least  two  feet 
above  the  highest  part  of  the  roof.  The  wind  will  travel  over 
the  roof  of  a  house  or  that  of  an  adjacent  building  and 
practically  cut  off  the  draft  of  a  low  chimney  beneath.  Fig. 
5  illustrates  this  condition,  the  arrows  indicating  the  direc- 
tion of  the  wind  and  the  dotted  portion  of  the  chimney  show- 
ing the  height  to  which  it  should  have  been  erected. 

Area  and  Height  Required. 

A  chimney  has  two  principal  factors — area  and  height. 

There  must  be  sufficient  area  to  pass  the  volume  of  air 
required  to  properly  burn  the  fuel.  Three  hundred  cubic 
feet  of  air  is  necessary  to  supply  the  oxygen  required  to  con- 
sume each  pound  of  coal. 

For  example,  suppose  we  are  operating  a  furnace  having 
a  27  inch  grate,  the  rate  of  combustion  being  4  pounds  of 
coal  per  square  foot  of  grate  per  hour.  A  27  inch  grate  has 
practically  4  sq.  ft.  of  area,  hence  4X4=16,  the  number 
of  pounds  of  coal  required  per  hour;  and  16X300=4,800  cu. 
ft.  of  air  per  hour,  the  volume  iiecessary  to  properly  burn 
this  amount  of  fuel. 

One  authority  says:  "Each  atom  of  carbon  requires  for 
its  perfect  combustion  two  atoms  of  oxygen.  When  this 


FLUES  AND  CHIMNEYS  13 

union   is    effected   it   burns    to    carbon   dioxide   and   yields   per 
pound  14,500  B.T.U.   (heat  units). 


Fig.  4 — 'Offset  Flue  Showing  Accumulation  of  Soot. 

"If,  however,  through  insufficient  air  supply  there  is  but 
one  atom  of  oxygen  to  one  of  carbon,  the  result  is  carbon 
monoxide  yielding  4,500  B.T.U.,  or  less  than  one-third  the 
heat  given  off  where  combustion  is  perfect." 


Fig.  5 — Effect  of  Wind  on  a  Low  Chimney. 

We  know  the  statement  of  this  chemist  to  be  true,  be- 
cause it  has  been  demonstrated  that  when  the  flue  is  too  small 
and  too  little  air  passes  upward  through  the  coal,  the  fire  has 
nc  life  or  activity,  and  the  fuel  is  consumed  without  pro- 
ducing effective  results. 


14  FLUES  AND  CHIMNEYS 

The  height  of  the  flue  should  be  sufficient  to  clear  the 
roof  of  the  building  or  any  surrounding  roofs  or  obstacles, 
so  that  the  wind  striking  the  roof  will  not  cut  off  the  draft  by 
being  deflected  over  the  top  of  the  chimney,  as  illustrated  by 
Fig.  6,  which  gives  another  example  of  the  action  of  the 
wind  upon  a  low  chimney. 


Fig.  6 — Illustrating  Action  of  the  Wind  Upon  a  Low  Chimney. 


The  height  (preferred)  of  the  chimney  for  the  average 
house  is  from  30  to  40  feet,  and  this  height  is  sufficient  for 
the  velocity  or  sharpness  of  draft  demanded. 

Many  owners  of  buildings  have  mistaken  intensity  of 
draft  for  volume,  and  many  heating  contractors  test  chimneys 
by  setting  fire  to  a  newspaper  and  crowding  the  same  into 
the  chimney  flue  through  the  opening  for  the  smoke  pipe. 
If  the  charred  paper  goes  up  the  flue  with  a  roar  they  think 
the  chimney  is  perfectly  satisfactory.  The  fact  is  that  a  six 
inch  pipe  would  show  exactly  the  same  results. 


FLUES  AND  CHIMNEYS  15 

How  Correct  Tests  Are  Made. 

Draft  gauges  of  various  kinds  are  used  for  testing  pur- 
poses. Among  heating  engineers  the  strength  of  draft  in  a 
chimney  is  measured  by  the  inches  of  water  required  to 
equalize  it. 

Fig.  7  illustrates  a  portable  draft  gauge  with  a  funnel. 
A  piece  of  glass  testing  tube  is  heated  and  bent  to  the  form 
shown.  The  funnel  is  made  of  tin  and  is  of  sufficient  size  to 
cover  the  ordinary  smoke  pipe  hole  of  the  chimney.  Some 
felt  cloth  or  soft  felt  paper  tacked  or  pasted  around  the  smoke 
pipe  opening  will  allow  the  funnel  to  seal  the  opening  tightly 
and  thus  will  show  more  accurate  results.  A  gauge  scaled 
in  inches  and  tenths  of  an  inch  is  adjusted  into  the  upright 
end  of  the  tube  as  shown.  The  tube  is  fastened  to  the  small 
end  of  the  funnel  with  plaster  of  Paris  and  is  filled  with  water 
to  a  point  one-half  way  up  the  scale. 


Fig.  7 — Portable  Draft  Gauge  with  Funnel. 


A  column  of  water  28  inches  high  (or  to  be  exact,  27.77) 
is  the  equivalent  of  one  pound  presure. 

In  reading  the  testing  gauge  the  difference  in  height  be- 
tween the  two  columns  should  be  noted.  If  a  chimney  draft 
was  balanced  by  a  column  of  water  one  inch  high  the  strength 
of  the  draft  would  be  1/28  of  a  pound  per  square  inch  of  area. 
The  chimney  draft  of  a  good  flue  will  equal  at  least  .2  of  an 
inch  of  water,  as  shown  by  the  scale. 


i6 


FLUES  AND  CHIMNEYS 


If  a  bent  glass  tube  can- 
not be  procured,  or  if  the 
heating  contractor  cannot 
bend  a  tube,  a  draft  gauge 
as  illustrated  by  Fig.  8 
may  be  made  of  straight 
pieces  of  glass  tube  and 
some  short  pieces  of  rub- 
ber tubing.  A  small  piece 
of  iron  pipe  is  inserted  into 
the  smoke  flue  and  the 
draft  gauge  attached  as 
shown. 

The  following  table  com- 
piled by  a  standard  author- 
ity may  be  used  in  connec- 
tion with  the  testing  gauge : 

Fig.  8 — A  Simple  Draft  Gauge  Easily  Constructed. 


Height, 

water, 

in  inches. 

.1 
.2 

•3 
4 
•5 
.6- 

7 
.8 

•9 
i.o 
i.i 

1.2 
1-3 
M 
1-5 

1.6 

17 

1.8 
1.9 

2.0 


Pressure 

in  Ibs. 
per  sq.  ft. 

•521 
1.042 

I-563 
2.084 
2.605 
3.126 


4.168 
4.689 
5.210 

5-731 
6.252 

6773 
7.294 

7.815 
8.336 
8.857 
9.378 
9.899 
10.420 


Velocity, 
ft.  per  sec. 

15.05 

21.3 

26.06 

30.1 

33-6 

36.8 

39-8 

42.5 

45-1 

47-5 

49-9 

52.1 

54.2 

56.3 
58.2 
60.2 
62.0 
63.8 
65.6 
67.3 


Velocity, 
ft.  per  min. 

903 
1278 

1564 
1806 
2Ol6 
2208 
2388 

2550 
2706 
2850 
2994 
3126 
3252 
3378 
3492 
3612 
3720 
3828 
3936 
4038 


FLUES  AND  CHIMNEYS 


The  area  of  a  flue  must  be  determined  by  measurement, 
as  no  form  of  testing  will  give  the  requirements,  which  are 
determined  by  the  work  in  hand.  The  size  of  furnace  to  be 
connected  with  the  flue  determines  the  area  required. 

Suppose  a  furnace  with  an  8-inch  smoke  outlet  is  re- 
quired. An  8  inch  pipe  has  an  area  of  50.265  square  inches, 
and  under  the  most  favorable  circumstances  of  draft  a  round 
flue  less  than  8  inches  in  diameter  or  a  square  flue  8X8  inches 
in  size  should  not  be  used.  If  a  rectangular  flue  is  provided, 
the  narrow  sides  of  the  same  should  not  be  less  than  8  inches. 

The  following  table  of  flue  areas  will  serve  as  a  guide  to 
flue  construction,  it  being  assumed  that  the  chimney  is  from 
forty  to  sixty  feet  in  height,  or  such  as  would  be  used  for  a 
two  or  three  story  building: 


TABLE  OF  FLUE  SIZES. 


Equivalent 

cubic  feet  of 

space  to  be  heated. 

10,000  to     15,000 

15,000  to    25,000 

25,000  to    40,000 

40,000  to     75,ooo 

75,000  to  125,000 

125,000  to  200,000 


Round  tile, 

Rectangular 

standard 

tile, 

sizes. 

standard  sizes. 

8  in. 

8^  x   &/2  in. 

10  in. 

Sl/2  x  13      in. 

12  in. 

13     x  13       in. 

16  in. 

13     x  18      in. 

20  in. 

18     x  18      in. 

24  in. 

18     x20T/2  in. 

Brick, 
inside  di- 
mensions. 
8x    8  in. 
8x  12  in. 
12  x  12  in. 
12  x  16  in. 
i6x  16  in. 
16x20  in. 


When  soft  coal  is  used  as  fuel,  25  per  cent,  should  be 
added  to  the  rated  size  of  flue. 

Location  of  the  Chimney. 

We  have  previously  mentioned  city  built  houses  and  the 
character  of  their  construction  ;  in  connection  therewith  there 
is  another  point  which  should  be  considered  in  providing  the 
chimneys.  They  are  usually  built  in  the  party  wall  separating 
the  parlors  or  front  rooms  and  the  custom  in  this  respect  fre- 
quently locates  the  flue  but  ten  feet  or  less  from  the  front 
wall  of  the  building.  No  matter  in  which  direction  the  house 
faces  the  chimney  will  be  found  in  the  same  location.  Sup- 
pose the  structure  be  five  rooms  deep ;  it  may  extend  from 
eighty  to  one  hundred  feet  from  front  to  rear  wall.  Again, 
suppose  the  house  faces  the  south,  the  chimney  being  within 
ten  feet  of  the  front  wall;  it  is  then  necessary  to  run  the 
warm  air  pipes  from  fifty  to  seventy  feet  toward  the  north, 
a  condition  beyond  all  reason  to  insure  satisfactory  and 
economical  service. 

The  chimney  should  be  centrally  located,  to  the  north 
and  west  rather  than  to  the  south  and  east  in  order  that  the 
longer  warm  air  supply  pipes  may  extend  to  and  serve  rooms 


i8 


FLUES  AND  CHIMNEYS 


on  the  south  and  east  sides  of  the  building,  and  the  shorter 
and  more  direct  pipes  to  those  rooms  on  the  north  and  west 
sides  of  the  building. 

If  possible  to  do  so,  it  is  well  to  erect  the  chimney  up 
through  the  center  of  the  building  where  the  greater  part  of 
it  will  be  surrounded  by  warm  air,  or  rooms  which  are  heated. 
In  such  a  flue  the  smoke  will  not  condense  so  rapidly,  nor  the 
gases  cool  as  quickly  as  in  a  chimney  built  in  an  outside  wall. 
When  a  chimney  flue  is  erected  in  an  outside  wall  it  should 
be  two  bricks  thick  on  the  outside  and,  if  possible,  should 
be  provided  also  with  an  air  space  between  the  bricks,  as 
illustrated  by  Fig.  9.  This  air  space  should  be  closed  and 
sealed  at  the  roof  line. 


—  DEAD  AIR  SPACE 


Fig.  9 — Air  Space  on  Exposed  Side  of  Chimney. 


The  flue  for  use  of  the  heating  apparatus  should  have  no 
other  openings  than  that  at  the  top  and  that  for  the  smoke 
pipe.  It  should  extend  from  twelve  inches  to  two  feet  below 
the  smoke  pipe  opening  in  order  to  provide  a  pocket  for  the 
soot. 

We  have  called  attention  to  the  fact  that  the  smoke  and 
other  products  of  combustion  ascend  the  chimney  flue  spirally, 
and  therefore  a  round  chimney  is  the  best  form  of  chimney 
construction.  Next  in  efficiency  is  the  square  flue,  and  last 
the  rectangular  flue. 

Common  Sources  of  Trouble. 

In  connection  with  the  construction  of  the  chimney,  there 
are  some  points  which  should  have  careful  attention  of  the 
architect  and  owner  as  well  as  the  heating  contractor. 

Make  the  foundation  for  the  chimney  sufficiently  solid 
and  strong  to  support  the  weight  of  it.  We  have  known 
chimneys  having  two  flues  to  settle  and  break  an  opening 
between  the  flues,  thereby  destroying  the  draft,  as  illustrated 
by  Fig.  10. 

Beware  of  chimney  tops.  As  a  rule  not  more  than  one 
in  ten  of  the  chimney  tops  offered  for  sale  is  adequate  in  size 
or  will  improve  the  work  of  the  flue.  A  chimney  is  only  as 


FLUES  AND  CHIMNEYS 


large  as  its  smallest  area,  and  an  8XS-inch  flue  (64  sq.  in.) 
having  a  top  7  inches  round  (internal  diameter)  has  but  38.48 
sq.  in.  of  area. 


1 

!      1 

1 

N 

1 

1 

1 

1 

i        i 

1 

1 

1 

1         ! 

1 

1 

1 

I         1 

1 

1 

1 

1         1 

1 

1 

!         1 

1 

1 

1         i 

1 

1         1 

1 

1 

1         1 

Fig.  10— Partition  Walls  between  Flues  Frequently  Crack 
and  Spoil  the  Draft. 


Abrupt  offsets  should  not  be  made,  as  flues  of  this  nature 
clog  with  soot.  The  contractor  should  be  careful  to  make  the 
smoke  connection  of  the  size  called  for  by  the  furnace,  and 
should  not  reduce  the  pipe  to  save  breaking  out  and  en- 
larging the  smoke  pip.e  hole. 

Chimney  Flue  Troubles. 

Chimney  flue  troubles  are  many,  and  when  there  seems 
to  be  sufficient  height  and  area  look  for  trouble  from  one  of 
the  following  sources : 

(a)  The  smoke  pipe  may  protrude  so  far  into  the  flue  as 
to  cut  off  the  draft. 


2O  FLUES  AND  CHIMNEYS 

(b)  The  chimney  may  be  contracted  or  enlarged  at  some 
point.     A  chimney  is  only  as  large  as  its  area  at  its  smallest 
point.      An    enlargement    at    some   point    frequently   acts   as   a 
damper  to  reduce  the  velocity  of  the  draft. 

(c)  Loose  clean-cut  doors,  open  space  around  smoke  pipe 
collar,  or  cracks  in  the  flue  admit  cold  air  and  spoil  the  draft. 

(d)  There  may  be  openings  in  the  flue  for  other  smoke 
pipes  besides  that  provided  for  the  furnace.     A  flue  for  use 
of  a  heating  apparatus  should  not  serve  for  any  other  purpose. 

(e)  The    flue    may   be   plugged    with    soot   or   filled    with 
rubbish.     Birds  build  nests  in  chimneys,  and  falling  plaster 
and  soot  may  jam  in  the  flue,  particularly  if  there  is  an  offset 
in  the  chimney.    Two  or  three  pieces  of  brick  tied  in  a  burlap 
bag  drawn  up  and  down  the  flue  by  means  of  a  rope  is  a 
good  method  of  cleaning  it  of  soot  or  other  obstruction. 

These  are  some  of  the  ordinary  sources  of  trouble  with 
chimneys,  and  while  there  are  others  they  are  not  sufficiently 
common  to  cause  frequent  trouble. 

A  good  flue  is  a  delight  to  the  experienced  heating  en- 
gineer and  contractor,  while  a  poor  flue  is  a  bane  to  him  and 
a  source  of  trouble  and  expense  to  the  owner  of  the  building. 


CHAPTER    II 
THE    FURNACE 


Having  determined  that  the  chimney  flue  is  adequate 
for  the  requirements  demanded  of  it  and  that  its  location, 
if  possible,  is  at  such  a  part  of  the  building  as  to  prove  most 
efficient,  let  us  now  consider  the  heart  of  the  system;  the 
furnace  proper. 

History  of  the  Furnace 

The  hot  air  furnace  was  the  original  form  Which  de- 
veloped the  later  date  methods  of  heating,  and  its  advent,  or 
we  may  possibly  say  its  invention,  was  the  direct  result  of 
necessity.  Probably  many  of  our  readers  know  the  story  of 
the  introduction  of  the  furnace;  nevertheless  the  telling  of 
its  history  is  interesting  enough  to  bear  repetition.  The  open 
fireplace  had  been  found  to  be  extravagantly  wasteful  of  fuel 
and  inadequate  to  properly  heat  the  exposed  parts  of  a  room. 
The  fireplace  heater  and  later  the  stove  were  evolved  to  pre- 
vent this  waste  and  to  make  possible  a  means  to  locate  the 
source  of  the  heat  where  it  would  prove  most  effective. 

With  the  growth  of  the  country,  the  forests  were  cut 
away.  As  towns  and  cities  grew  in  size,  the  cost  and  in- 
convenience of  obtaining  fuel,  and  the  further  fact  that  this 
centralizing  of  business  and  the  people,  demanded  larger  and 
larger  buildings  to  accommodate  the  conditions,  made  it  im- 
perative that  some  method  should  be  produced  whereby  the 
labor  of  attending  so  many  fires  could  be  overcome. 

This  led  to  the  invention,  if  it  may  be  called  so,  of  the 
hot  air  furnace,  which  in  its  early  stage  was  nothing  more 
than  an  extremely  large  stove  encased  in  brick  combining, 
in  a  measure,  the  principles  of  Dr.  Franklin,  who  in  1744  in- 
vented the  wood  stove,  with  the  hollow  back  or  casing,  hav- 
ing an  air  duct  or  cold  air  tube  through  which  air  from  out- 
side the  building  was  heated  and  introduced  into  the  room  in 
which  the  stove  was  located. 

The  discovery  and  use  of  anthracite  coal  as  a  fuel  proved 
a  great  factor  in  developing  the  possibilities  of  furnace  heat- 
ing. The  early  development  of  the  furnace  was  largely  the 
result  of  experimenting  by  Mr.  Henry  Ruttan.  We  are  aware 
that  many  of  the  older  manufacturers  of  warm  air  heating 


22 


FURNACE  REQUIREMENTS 


apparatus  have  a  sort  of  "me  too"  argument  in  this  direction. 
It  is  certain,  however,  that  when  Mr.  Ruttan  in  1862  wrote 
the  following  words,  he  expounded  the  true  principles  of 
furnace  heating  and  ventilation,  principles  we  cannot  neglect, 
if  we  are  to  meet  with  success  in  our  work. 

Mr.  Ruttan  said :  "If  you  open  your  aperture  at  the  top, 
and  the  air  you  bring  in  is  warm,  or  if  you  open  the  aperture 
at  the  bottom,  and  the  air  you  bring  in  is  cold — in  either  case 


Fig.  ii — To  Ventilate  and  Cool  a  Room. 


the  body  of  air  will  not  budge ;  your  warm  air  will  go  through 
the  body,  straight  to  and  out  of  the  top  aperture ;  and  the  cold 
air  will  do  the  same  through  the  bottom  aperture.  The  con- 
sequence is  easily  seen — you  will  neither  warm,  cool,  nor 
ventilate  the  room." 

"If  you  want  to  ventilate  your  room  to  warm  it,  and 
open  the  bottom  aperture,  you  will  succeed  in  both ;  because 
the  fresh  air  will  be  the  warmest,  and  will  not  stop  until  it 
comes  in  contact  with  the  ceiling,  where  spreading  out  in  a 
level  strata  over  the  whole  ceiling,  it  will  keep  its  relative 
position  to  the  whole  body  until  it  reaches  the  bottom  and 
passes  out  through  the  aperture.  If  we  want  to  ventilate  our 
room  to  cool  it,  we  must  let  the  air  out  at  or  near  the  top. 


FURNACE  REQUIREMENTS  23 

"If  on  the  other  hand,  we  wish  to  ventilate  our  house  to 
warm  it,  we  must  take  the  air  out  at  or  near  the  bottom,  thus 
keeping  up  a  continual  exhaustion  of  the  heated  air;  and  if 
we  wish  to  set  the  whole  body  of  air  in  the  room  in  motion, 
upward  or  downward,  we  must,  of  course,  bring  in  the  neces- 
sary amount  of  outside  air  to  do  it." 


Fig.  12— To  Ventilate  and  Warm  a  Room. 

Figs,  ii  and  12  illustrate  these  principles,  and  to  those 
who  are  making  a  study  of  this  subject  we  recommend  that 
they  fix  them  indelibly  upon  their  minds,  as  they  combine  the 
true  principles  governing  hot  air  heating  and  ventilation. 

Character  and  Size  of  the  Furnace. 

It  is  not  our  purpose  to  comment  on  or  advocate  any 
particular  type  of  furnace,  except  in  a  general  way  to  note 
such  distinctive  features  as  will  assist  the  furnace  man  to  make 
the  proper  selection  for  any  work  in  hand. 

The  bricked-in  furnace  has  been  succeeded  by  the  more 
up-to-date  portable  setting,  or  casing,  and  except  in  very  old 
buildings  the  former  style  of  furnace  is  seldom  seen. 

The  grate  is  a  very  important  part  of  a  furnace.  Enough 
open  space  should  be  provided  to  permit  the  passing  of  suf- 
ficient air  to  meet  the  requirements  when  re-charging  with 


24  FURNACE  REQUIREMENTS 

fuel,  and  the  bars  should  be  strong  enough  to  carry  the  heavi- 
est load  without  sagging  or  binding. 

Beware  of  cheap  furnaces.  They  are  expensive  at  any 
price.  A  few  dollars  saved  in  the  price  of  the  furnace  itself 
must  result  in  the  furnishing  of  lighter  castings,  a  smaller 
capacity,  less  radiating  power,  and  cheaper  construction 
throughout. 

In  a  good  furnace  there  will  be  from  twenty-five  to  thirty 
square  feet  of  heating  surface  to  one  of  grate  surface.  There 
should  be  a  deep  fire  pot,  and  a  grate  of  sufficient  area  for  the 
work  in  order  that  the  rate  of  combustion  will  not  exceed 
four  pounds  of  coal  per  square  foot  per  hour  in  coldest 
weather.  Definite  rules  will  be  given  later  for  ascertaining 
the  proper  size  of  furnace  and  grate  area. 

The  gases  in  the  combustion  chamber  must  not  be  cooled 
by  allowing  the  cold  air  to  come  in  contact  with  the  outside  of 
this  chamber.  A  furnace  does  its  best  work  under  conditions 
of  perfect  combustion,  and  one  so  constructed  that  the  in- 
coming cold  air  will  be  partially  tempered  by  the  flue  gases 
in  their  exit  from  the  furnace  before  coming  in  contact  with 
the  hot  plates  of  the  combustion  chamber,  will  show  a  higher 
rate  of  efficiency  per  square  foot  of  grate  surface  than  will  a 
furnace  in  which  the  cold  air  passes  immediately  over  the  hot 
plates  or  heating  surfaces. 

If  the  chimney  flue  is  of  sufficient  size  and  is  properly 
constructed,  a  temperature  within  it  of  300  degrees  will  be 
more  than  adequate  for  perfect  draft.  The  excess  of  fuel  re- 
quired in  many  furnaces  is  due  not  only  to  poor  combustion, 
but  to  the  escape,  at  a  high  temperature,  of  the  gases  into  the 
chimney  flue.  By  bringing  the  cold  air  into  contact  with  the 
heat  of  these  gases  much  of  this  lost  heat  may  be  utilized 
and  saved.  In  the  construction  of  the  furnace  the  joints 
should  be  gas  proof  and  dust  proof  under  all  circumstances. 

Furnace  Casing  and  Top. 

All  furnace  casing  should  be  made  double  with  an  air 
space  between  the  inner  and  outer  casing  sufficient  to  act 
as  a  non-conductor  and  keep  the  outer  casing  cool.  Asbestos 
paper  or  mill  board  is  frequently  placed  between  these  two 
casings,  or  as  a  covering  for  the  outer  one.  This  is  not  a 
necessity,  however,  providing  there  is  sufficient  air  space 
between  the  inner  and  outer  casing.  Our  preference  is  for 
a  black  iron  inner  casing  and  a  galvanized  iron  outer  casing. 
No  single  cased  furnace  will  do  good  and  economical  work. 

There  are  many  opinions  as  to  the  proper  style  of  top 
or  bonnet.  The  style  used  may  be  in  a  measure  dependent 


FURNACE  REQUIREMENTS  25 

upon  the  height  of  the  cellar,  or  the  manner  in  which  the 
leader  pipes  are  attached.  Any  one  type  of  top  is  not  adaptable 
to  all  cases.  Fig.  13  illustrates  a  straight  side  flat  top,  hav- 
ing a  hoop  or  iron  band  around  the  top  to  hold  about  one 
inch  of  sand.  A  deflector  is  placed  on  the  inner  side  as  in- 
dicated by  the  dotted  lines.  The  leader  pipes  are  taken  off, 
back  of  or  on  the  inner  side,  of  the  deflector. 

Fig.  14  shows  a  common  form  of  pitch  top  to  which  the 
leaders  are  connected  by  bevel  elbows.     Unless  a  deflector  is 


i 


'SAND  BAND 


™7  

\ 

/  DEFLECTOR 

\ 

DEFLECTOR.^ 

£ 

\ 

Fig.  13— Straight  Side  Flat  Top  Bonnet 


Fig.   14 — Common   Form   of   Pitch   Top. 


1  SAND  BAND  % 


--..^  DEFLECTOR  Y^"' 
I)/  OR  2  BAND  x 


ASBESTOS 
CEMENT 


Fig.   15 — Desirable  Type  of  Bonnet. 


used  the  hot  air  will  short-circuit  into  the  shorter  and  more 
direct  leader  pipes. 

Fig.  15  illustrates  what  we  believe  to  be  the  very  best 
type  of  top.  The  deflector  has  a  deep  pitch  toward  the  center. 
Above  this  the  top  is  flat,  having  a  one-inch  sand  hoop  around 
the  edge.  The  bottom  is  provided  with  a  similar  hoop  one 
and  one-half  or  two  inches  wide  which  fits  tightly  over  the 
furnace  casing  and  protrudes  slightly  above  the  upper  edge. 
After  the  openings  for  the  leader  pipes  are  cut  in  and  the 
pipes  attached,  the  remaining  portion  of  the  pitched  side  of 


26  FURNACE  REQUIREMENTS 

the  top  is  covered  to  the  depth  of  one  inch  with  plastic  asbes- 
tos cement.  This  is  supported  in  position  by  the  extension 
of  the  -iron  band  fastening  the  top  to  the  casing.  The  casing 
being  double,  the  top  of  the  hood  being  protected  by  sand, 
and  the  sides  of  the  top  protected  with  asbestos  cement,  there 
can  be  no  loss  of  heat  from  the  furnace. 

All  leader  pipes  should  leave  the  top  at  the  same  level 
and  should  be  properly  aligned.  The  careful  alignment  of 
them  makes  not  only  a  better  looking  job,  but  a  better  work- 
ing one  as  well.  Do  not  take  the  leader  pipes  from  the  top 
and  from  the  side  on  the  same  job.  Air  will  move  toward  the 
point  of  least  resistance,  and  heated  or  expanded  air  will  move 
vertically  through  the  nearest  aperture;  therefore  the  leader 
pipes  taken  from  the  top  will  rob  those  taken  from  the  side. 

We  know  a  furnace  man  who  thinks  it  best  to  take  the 
longer  runs  from  the  top  and  the  shorter  runs  from  the  side, 
and  strange  to  say  he  has  considerable  success.  Human 
ingenuity,  however,  is  many  times  a  failure,  and  we  prefer 
to  stick  to  methods,  which  have  proven  successful. 

Location  of  the  Furnace. 

In  locating  the  furnace  many  of  the  details  entering  into 
the  construction  of  the  building,  such  as  the  position  of  the 
piers  or  posts  supporting  girders,  the  position  of  division 
walls,  of  the  chimney  flue,  etc.,  must  be  taken  into  considera- 
tion. When  the  north  and  west  sides  are  well  protected  from 
the  prevailing  winds  of  the  winter  season,  the  furnace  should 
set  as  near  to  the  center  of  the  building  as  conditions  will 
allow.  When  the  building  is  exposed  on  all  sides  the  furnace 
should  be  placed  more  to  the  north  and  west  of  the  center, 
and,  provided  the  chimney  has  been  built  in  accordance  with 
our  suggestions  given  in  the  second  article  of  this  series,  this 
location  is  made  available  without  the  use  of  a  long  smoke 
pipe.  Under  ordinary  conditions  the  furnace  should  set  not 
more  than  6  feet  distant  from  the  chimney  flue.  The  warm 
air  pipes  supplying  the  rooms  to  the  north  and  west,  or  to 
the  principal  rooms  on  the  first  floor,  should  be  as  short  as 
possible.  It  is  far  better  to  double  the  length  of  the  smoke 
pipe,  if  necessary,  to  locate  the  furnace  to  the  north  and  west, 
than  it  is  to  double  the  length  of  the  warm  air  pipes,  if  con- 
tingencies arise  which  make  it  imperative  to  select  between 
the  two  courses. 

Methods  of  Setting. 

We  are  aware  that  many  of  those  engaged  in  the  busi- 
ness of  installing  furnaces  have  their  individual  opinions  as  to 
the  correct  method  of  setting  a  furnace.  However,  while  we' 


FURNACE  REQUIREMENTS  27 

respect  such  motives  it  would  seem  to  the  writer  that  some 
furnace  men  are  inclined  to  stick  to  certain  methods  and 
principles  simply  because  they  have  had  more  or  less  suc- 
cess in  one  particular  direction  by  following  the  usual  method. 
The  up-to-date  furnace  man  should  permit  existing  conditions 
to  shape  the  method  of  setting  the  furnace,  and  he  should  be 
competent  to  judge  what  particular  method  of  the  number 
in  vogue  is  best  suited  to  the  job  in  hand.  Some  furnace  men 
are  careless  in  their  methods  of  preparation  for  the  installa- 
tion of  a  furnace,  frequently  setting  the  furnace  directly  on 
the  dirt  cellar  bottom  when  it  seems  sufficiently  hard  to  sup- 
port its  weight.  This  method  results  in  a  source  of  dirt  and 
dust.  The  heat  in  the  ash  pit  will  dry  out  the  earth  so  that 
the  jarring,  incident  to  attending  and  shaking  down  the  fire, 
will  cause  particles  of  dirt  to  be  carried  upwards  and  into  the 
rooms  by  the  air  currents  passing  through  the  furnace. 

The  best  practice  is  to  build  a  cold  air  pit  under  the  fur- 
nace, such  as  is  illustrated  by  Fig.  16.  The  brick  pier  shown 
in  the  center  will  support  the  weight  of  the  furnace  and  assist 
in  dividing  the  cold  air  supply.  Note  that  a  corner  of  the  pier 
is  toward  the  cold  air  duct,  thus  allowing  an  equal  distribu- 
tion of  the  cold  air  to  each  side  of  the  furnace. 


';'••.•_-•-.     •-••••.  •!.•"— : -.-.».„..<• 

.  :=Ll==;.::!i=::is-!>i- 


Fig.  16— The  Cold  Air  Pit. 

The  pit  should  not  be  less  than  12  inches  nor  more  than 
16  inches  in  depth.  In  building  it  a  place  should  be  excavated 
of  sufficient  depth  to  allow  a  filling  of  broken  stone  or  brick 
about  4  inches  deep.  This  should  be  covered  by  a  layer  of 
coarse  sand  and  cement,  leveled  and  well  tamped  down.  The 
floor  of  the  pit,  which  is  also  the  foundation  for  the  wall  and 
pier,  should  be  constructed  of  brick  laid  in  cement  and 
plastered  smooth.  This  may  add  a  trifle  to  the  cost  of  installa- 
tion, but  will  prove  in  the  end  to  afford  the  most  satisfactory 
job. 

Frequently,  because  of  the  low  location  the  building  oc- 
cupies, there  is  trouble  from  water  if  excavation  is  made  be- 
low the  surface  of  the  cellar  floor,  and  in  such  cases  the  air 
duct  must  be  connected  to  the  furnace  above  the  floor  level. 


28  FURNACE  REQUIREMENTS 

For  this  purpose  a  special  type  of  casing  must  be  used,  as 
illustrated  by  Fig.  17.  The  frame  of  the  opening  shown  is 
called  a  shoe.  Do  not  connect  the  cold  air  into  a  shoe  on  one 
side  of  the  casing  only,  as  this  style  of  connection  will  not 
afford  sufficient  air  to  the  opposite  side  of  the  furnace,  as  the 


Fig.   17 — Casting  for  Use  when  Cold  Air  Duct  is  Above  Floor. 

air  space  through  the  furnace  bottom  around  the  ash  pit  and 
fire  pot  is  shaped  very  much  like  a  horseshoe,  as  seen  in 
Fig.  18.  The  shoe  should  be  placed  at  tjie  rear,  or,  what  is 
better,  a  sparate  opening  or  shoe  should  be  provided  for  con- 
necting the  air  into  either  side. 


Fig.  18 — Proper  Location  of  Shoe  for  Cold  Air  Duct 

Care  should  be  exercised  in  setting  a  furnace  to  care- 
fully cement  or  pack  all  joints  where  they  are  necessary,  and 
the  casing  should  be  fit  absolutely  air  tight.  Loose  joints  in 
the  furnace  castings  will  allow  dust  and  gas  to  enter  the  warm 
air  distributing  pipes,  and  a  leaky  casing  interferes  with  the 
proper  working  of  a  furnace  precisely  in  the  same  manner 
as  a  leaky  chimney  interferes  with  the  draft. 


FURNACE  REQUIREMENTS 


29 


Fig.  19— Three  Methods  of  Supplying  Cold  Air. 


30  FURNACE  REQUIREMENTS 

The  furnace  must  set  sufficiently  low  to  insure  giving  the 
proper  pitch  to  the  longest  warm  air  pipes,  and,  if  necessary 
to  secure  this  desired  feature,  the  furnace  may  be  placed  in 
a  pit.  When  conditions  make  this  course  essential,  build  the 
pit  of  ample  size  and  allow  plenty  of  room  for  setting  the 
furnace.  Sufficient  space  should  also  be  provided  in  the  pit 
at  the  front  of  the  furnace  to  facilitate  the  removal  of  ashes 
and  the  work  of  attending  to  the  apparatus. 

The  Cold  Air  Supply. 

The  furnishing  of  an  adequate  amount  of  cold  air,  to- 
gether with  a  proper  manner  of  supplying  the  furnace  with 
it,  is  no  doubt  the  key  to  successful  hot  air  heating,  and  we 
can  therefore  consider  this  the  most  important  part  of  furnace 
installation.  An  inspection  of  present  day  furnace  work  in 
some  localities  would  in  ninety-nine  jobs  out  of  every  hundred 
either  show  no  provision  whatever  for  an  outside  cold  air 
supply  or,  if  provided,  it  would  be  an  ill-shaped  or  leaky  duct 
made  of  rough  boards.  It  is  just  as  important  to  eliminate 
all  possible  friction  from  the  movement  of  the  cold  air  as  it 
is  to  provide  easy  movement  of  the  heated  air.  Where  a  gal- 
vanized iron  duct  is  attached,  curved  elbows  should  be  used 
rather  than  miter  elbows,  and  the  cold  air  pipe  should  drop 
to  the  floor  at  an  angle  instead  of  pitching  down  vertically. 

Fig.  19  shows  three  methods  of  supplying  cold  air,  the 
sketch  on  the  left  illustrating  a  common  type  of  wood  boxing 
frequently  found  on  cheap  work.  The  center  illustration 
shows  a  duct  made  of  galvanized  iron,  a  marked  improvement 
over  the  former,  which  can  be  still  further  bettered,  however, 
by  the  use  of  curved  elbows,  as  shown  on  the  right.  This 
latter  type  of  duct  may  be  easily  connected  to  an  underground 
tile,  and,  when  provided  with  a  cold  air  chamber  or  air  cleans- 
ing box  on  the  inside  of  the  opening  through  the  cellar  wall, 
it  makes  an  admirable  method  of  handling  the  fresh  air. 

In  towns  or  cities  where  trouble  is  experienced  from  dust 
or  soot  laden  air,  it  is  advisable  to  filter  or  cleanse  the  supply 
by  means  of  cheesecloth  baffles.  There  are  numerous  plans 
of  using  these  cleansing  baffle  cloths,  but  only  one  general 
method.  The  outside  air  upon  entering  the  basement  flows 
into  a  cold  air  chamber,  striking  at  a  sharp  angle  a  series  of 
filter  screens  partially  covered  with  cheesecloth,  which  are 
set  in  the  cold  air  chamber  at  such  an  angle  that  the  incom- 
ing supply  is  compelled  to  make  a  number  of  right  angle 
turns  in  passing  the  baffles.  The  chamber  should  be  as- 
sembled in  such  a  manner  that  one  side  (in  the  form  of  a 
door)  opens  to  permit  the  ready  removal  of  the  screened 


FURNACE  REQUIREMENTS  31 

frames  for  cleaning.  Do  not  use  starched  muslin  or  cloth  of 
smooth  texture  for  this  purpose.  The  rougher  the  surface  of 
the  cloth  the  better  will  be  the  results  obtained.  Some  recom- 


Fig.   20— Air   Filter   Having   Cloth   Baffles. 

mend  that  the  cloth  screens  be  coated  with  oil  to  assist  in 
collecting  the  dust,  but  we  have  found  cheesecloth  well  suited 
to  the  purpose  without  such  a  coating. 


Fig.  21 — Air  Filter  Having  Wooden  Baffles. 

Another  style  is  made  of  permanent  wood  baffles  so  ar- 
ranged that  the  first  one  next  to  the  fresh  air  inlet  acts  as  a 
deflector,  precipitating  a  large  portion  of  the  dust  to  the  bot- 
tom of  the  box  or  chamber. 


32  FURNACE  REQUIREMENTS 

The  two  styles  are  illustrated  in  Figs.  20  and  21,  using 
for  illustration  that  recommended  by  prominent  furnace  manu- 
facturers, which  method  cannot  be  too  highly  commended. 
These  screens  not  only  filter  the  supply,  but  also  act  as  a 
damper  to  control  the  velocity  of  the  incoming  air  before  it 
enters  the  cold  air  duct.  As  the  inlet  for  cold  fresh  air  should 
be  on  the  north  or  west  side  of  the  building  it  is  necessary 
to  make  some  provision  for  controlling  the  velocity  of  the 
prevailing  winds  of  winter,  and  this,  as  well  as  the  cleansing 
of  the  air,  is  accomplished  by  the  method  illustrated. 

The  cold  air  from  outside  the  building  should  enter  the 
furnace  through  the  pit.  The  recirculated  air  should  be  con- 
nected to  furnace  by  attaching  the  piping  to  shoes  on  either 
side  of  the  casing,  or,  if  necessary  to  connect  the  inside  cold 
air  ducts  into  the  main  cold  air  supply,  they  should  enter  this 
duct  in  such  a  manner  that  there  will  be  no  possibility  of 
the  cold  air  entering  the  circulating  ducts.  Fig.  22  illustrates 
one  method  of  accomplishing  this  result. 


CIRCULATING  DUCT 


OUTSIDE  AIR 


i 

\ 

_L 


C/RCULAT/NG  DUCT- 

Fig.  22 — Combining  Recirculated  Air  with  Cold  Air. 

Some  furnace  men  claim  that  all  ducts,  both  outside  and 
inside,  should  be  arranged  with  dampers  so  that  one  or  the 
other  system  only  may  be  used.  Our  experience  has  been 
that  occupants  of  a  building  will  not  give  the  required  atten- 
tion to  dampers,  or,  if  they  attend  to  them  at  all,  will  not  do 
so  properly.  We  therefore  recommend  the  connection  shown 
by  Fig.  22  which  should  be  installed  without  dampers  of  any 
kind  other  than  a  single  one  by  which  the  outside  cold  air 
can  be  entirely  shut  off  when  a  recirculation  of  the  inside  air 
only  is  desired.  It  is  understood  that  the  outside  cold  air 
is  taken  from  a  cold  air  chamber,  which  will  control  the  flow 
of  air  in  windy  weather  and  which  is  not  directly  connected 
to  the  outside. 

In  area,  the  ^old  air  duct  should  be  three-quarters  that 
of  all  of  the  warm  air  pipes  leading  from  the  furnace  top. 
We  think  this  rule  is  very  generally  known  among  furnace 
men,  and,  while  not  absolutely  accurate,  is  sufficiently  so 


FURNACE  REQUIREMENTS  33 

for  all  purposes.  These  conditions  do  not  hold  in  figuring  the 
capacity  of  the  ducts  for  recirculation  of  the  inside  air.  These 
ducts  should  be  equal  in  area  to  the  warm  air  pipes,  or  nearly 
so. 

To  arrive  at  the  proper  size  of  the  cold  air  duct  we  figure 
on  the  expansion  of  the  outside  air  when  heated  to  a  normal 
degree.  For  the  recirculating  ducts  we  figure  on  the  quantity 
of  air  delivered  by  the  warm  air  pipes,  which,  after  supplying 
heat  to  the  various  rooms,  is  not  cooled  sufficiently  to  make 
any  considerable  depreciation  in  its  bulk  or  volume. 

Size  of  Furnace  Required. 

The  furnace  man  is  held  responsible  by  the  furnace  man- 
ufacturer for  most  of  the  trouble  and  for  the  largest  share  of 
the  present  condemnation  of  the  furnace  and  of  warm  air 
heating.  Are  the  trade  justly  open  to  criticism  or  are  the 
manufacturers  at  fault?  This  question  is  of  interest  to  every 
person  who  desires  to  see  this  class  of  heating  work  elevated 
to  a  higher  standard. 

The  furnace  man  is  at  fault  in  adopting  methods  neces- 
sitating cheap  competitive  work.  The  manufacturers  are, 
however,  the  chief  offenders.  Before  proceeding  further  per- 
mit us  to  insert  a  word  of  praise  for  those  manufacturers  who 
are  giving  definite  information  to  the  furnace  man  as  to  the 
ratings  of  their  furnaces,  best  methods  of  installation,  etc., 
and  who  are  placing  conservative  ratings  on  their  goods. 
We  think  it  is  not  stating  the  case  too  strongly  when  we 
declare  that  one-half  the  hot  air  furnaces  produced  are  grossly 
overrated. 

If  furnace  heating  is  to  be  placed  on  the  higher  plane  it 
deserves  there  are  many  manufacturers  who  must  rate  their 
furnaces  on  a  more  conservative  basis.  The  practice  of  de- 
termining ratings  on  the  basis  of  casing  sizes  must  be  dis- 
continued. All  methods  of  figuring  capacities  that  do  not 
take  into  consideration  the  cooling  surfaces  of  a  building — 
i.  e.,  the  heat  losses  through  glass  (windows),  outside  doors 
and  walls — when  computing  the  necessary  size  of  furnace, 
must  be  abolished  if  we  are  to  meet  with  success. 

Last,  but  not  least,  the  evil  practice  of  selling  furnaces 
to  any  one  who  has  the  money  to  buy  and  pay  for  them,  with- 
out regard  to  the  purchaser's  fitness  and  ability,  or  to  his 
knowledge  as  a  furnace  man,  must  cease  if  clap-trap  methods 
and  cheap  competition  are  to  be  overcome.  If  the  past  prac- 
tices are  allowed  to  prevail  we  shall  reach  that  stage  where 
the  owner  will  refuse  to  pay  for  his  furnace  until  he  has  had 
at  least  one  winter's  trial  of  the  apparatus  and  assured  him- 
self of  its  satisfying  qualities. 


34  FURNACE  REQUIREMENTS 

We  shall  not  presume  to  dictate  to  manufacturers  how 
they  shall  rate  their  furnaces.  In  view  of  the  exigency  of  the 
case  they  should,  however,  adopt  a  basis  by  which  all  cooling 
surfaces  of  a  building  are  reduced  to  an  equivalent  from 
which  the  schedule  of  the  probable  performance  of  the  fur- 
nace can  be  made,  and  from  which  the  furnace  man  can 
select  the  size  suited  to  any  purpose. 

The  heating  surface  of  the  furnace  must  be  sufficient  to 
warm  the  amount  of  air  the  cubical  contents  of  the  building 
will  demand,  and  the  air  outside  of  the  building  is  always 
cooler  than  the  air  within.  It  is  a  law  of  nature  that  the 
temperatures  of  adjacent  bodies  will  equalize.  A  certain 
portion  of  the  heat  is  diffused  or  lost  by  transmission  through 
walls  and  windows;  therefore  the  furnace  must  not  only  be 
large  enough  to  heat  the  air  within  the  building  with  from 
two  to  four  changes  of  air  per  hour,  but  it  must  also  have 
sufficient  capacity  to  compensate  for  the  losses  by  diffusion. 
The  heat  losses  in  two  buildings  are  never  the  same  and  yet 
when  reduced  to  equivalent  glass  surfaces  or  equivalent  wall 
surface  they  are  easily  determined. 

Manufacturers  of  steam  and  water  warming  apparatus 
have  based  their  ratings  on  these  factors  and  the  steam  fitter, 
by  any  one  of  a  dozen  rules,  can  determine  accurately  just 
what  size  of  boiler  is  necessary  for  any  particular  require- 
ment. 

Let  us  see  how  readily  this  style  of  figuring  may  be  adapted 
to  the  furnace.  We  will  take  for  example  a  house  30  by  40  feet, 
having  ten  rooms  to  be  heated.  The  house  has  twenty  windows 
averaging  3  by  6  feet,  and  three  outside  doors  3  by  8  feet  (in- 
cluding transoms).  First  floor  ceilings  are  10  feet,  and  second 
floor  ceilings  9  feet  high.  The  approximate  cubical  contents  to 
be  warmed  would  be: 

30  X  40  X  10  plus  30  X  40  X  9,  or  22,800  cubic  feet. 
The  glass  surface  (doors  counted  as  glass)  would  be: 
3'  x  6'  =  18  X  20  =  360 
3'X8'  =  24X    3=    72 


Total  glass  surface 432  square  feet. 

The  wall  surface  would  be: 
30  +  40  =  70  X  2  =  140  X  19  (height  of  ceilings )=  2, 660  sq.  ft. 

Assuming,  as  we  properly  may,  that  4  square  feet  of  exposed 
wall  equals  I  square  foot  of  glass  in  cooling  surface  or  heat  loss, 
we  have : 

2,660-^-4  =  665, 
the  glass  equivalent  of  the  wall  surface,  which,  plus  432,  the 


FURNACE  REQUIREMENTS  35 

square  feet  of  actual  glass,  gives  the  total  equivalent  of  glass 
as  1,097  square  feet. 

Let  us  figure  on  two  changes  of  air  per  hour,  and  the  total 
amount  of  air  to  be  warmed  hourly  will  be  22,800X2,  or  45,600 
cubic  feet.  The  loss  of  heat  by  transmission  through  ordinary 
glass  windows  is  determined  as  being  approximately  0.8  B.  T.  U. 
(British  Thermal  Units)  per  square  foot  per  hour,  per  degree 
difference  in  temperature,  or,  in  other  words,  in  this  case  the 
outside  temperature  being  at  o°  (zero)  and  the  temperature  of 
the  rooms  70°,  the  difference,  70° — o°,  would  be  70°;  therefore, 

1,097  X  0.8  X  70  =  61,432  B.  T.  U. 

We  also  know  that  one  heat  unit  will  raise  55  cubic  feet  of 
air  one  degree  in  temperature.  Assuming  that  the  hot  air  at 
the  registers  enters  the  rooms  at  120°,  we  proceed  as  follows: 

45,600  -f-  55  X  120  =  99,480  B.  T.  U. 

A  good  quality  of  anthracite  coal  contains  approximately 
14,500  heat  units,  of  which  about  10,000  are  actually  available 
for  heating  in  a  properly  constructed  furnace  with  a  combustion 
of  3  pounds  of  coal  per  square  foot  of  grate  per  hour ;  therefore, 
10,000  X  3  =  30,000  B.  T.  U.  per  hour  per  square  foot  of  grate. 

To  arrive  at  the  correct  size  of  grate  to  properly  heat  this 
house  we  add  the  required  heat  units,  61,432  -(-  99,480  =  160,912, 
and  divide  by  30,000  =  5.36  square  feet.  Therefore  we  require 
a  grate  having  5.36  square  feet  of  area. 

This  is  based  on  zero  weather  for  the  winter,  and,  judging 
from  the  present  rating  of  some  furnace  manufacturers,  they 
are  taking  long  chances  and  are  expecting  mild  weather  the 
better  part  of  the  heating  season. 


CHAPTER  III 
PIPE,    FITTINGS   AND  REGISTERS 


Furnace  fittings  such  as  elbows,  boots,  offsets,  tees,  etc.,  are 
made  in  a  great  variety  of  shapes,  the  construction  and  patterns 
for  which  are  treated  by  William  Neubecker  in  the  concluding 
portion  of  this  book. 

We  desire  particularly  to  call  attention  to  some  common  errors 
and  offer  suggestions  for  their  correction.  In  considering  the 
question  of  piping  a  job  of  furnace  heating,  we  should  naturally 
suppose  that  the  later  day  advanced  methods  were  far  superior 
to  those  used  years  ago.  Investigation  would  reveal  that  in 
many  respects  this  is  true — also  that  in  almost  as  many  other 
respects  it  is  not  the  case.  The  old  plan,  followed  in  the  early 
days  of  warm  air  heating,  of  running  round  or  square  flues  or 
risers,  has  not  been  improved  upon  up  to  this  time  in  so  far  as 
good  service  is  concerned.  True,  there  have  been  marked  im- 
provements in  the  designs  of  boots,  tees  and  register  boxes,  but 
are  these  improvements  such  that  they  have  a  bearing  on  the 
reduction  of  friction  or  on  increasing  the  flow  of  air  through 
the  piping?  We  think  that  they  concern  principally  the  money 
end  or  cost  of  the  work.  The  infinite  variety  of  stock  patterns 
of  all  kinds  of  furnace  pipe  fittings,  such  as  adjustable  elbows 
and  the  like,  make  it  easier  and  quicker  to  install  a  job,  but  for 
all-around  efficiency,  give  us  the  furnace  work  of  the  good  old 
days,  when  round  or  square  risers  were  used,  when  all  joints 
were  soldered  and  the  fittings  were  shaped  on  the  job,  being  made 
to  conform  to  the  conditions  of  the  work. 

The  flow  of  air  through  piping  is  one  of  the  first  parts  of  the 
business  that  should  be  studied  by  the  furnace  man.  The  illus- 
tration, Fig.  23,  represents  a  12  inch  diameter  round  pipe  supply- 
ing a  3^  by  12  inch  riser.  Friction?  Yes!  and  plenty  of  it. 
The  flow  of  air  in  a  pipe  the  area  of  which  is  113  square  inches 
is  attempting  to  enter  a  pipe  the  area  of  which  is  but  42  square 
inches,  or  nearly  two-thirds  less  in  capacity.  This  shows  a  con- 
dition frequently  found  on  present  day  furnace  installations. 
Follow  the  effect  of  work  of  this  character  down  to  the  furnace 
and  it  will  develop  that  the  principal  results  attained  will  be  an 


HEATING  EQUIPMENT 


37 


excessive  coal  consumption  and  a  shortening  of  the  life  of  the 
furnace  due  to  an  overheating  of  its  castings. 


/<?' 'ROUND -113°" 
Fig.  23 — Two  Much  Taper,  Causing  Friction. 

How  may  this  evil  condition  be  avoided?  This  question  nat- 
urally follows.  And  the  answer  is — by  enlightening  the  architect 
as  to  its  dangers,  and  at  the  same  time  having  partitions  provided 
in  the  buildings  in  which  flues  of  suitable  shape  and  area  may 
be  installed.  Note  by  illustration,  Fig.  24,  such  a  partition  furred 
out  to  accommodate  two  8-inch  round  flues,  one  supply  an  8 
by  lo-inch  first  floor  register,  the  other  feeding  a  second  floor 
room.  An  8  inch  round  pipe  having  an  area  of  50  square  inches 
will  give  as  good  service  as  an  8  by  8-inch  square  pipe,  although 
the  area  of  the  latter  is  64  square  inches.  It  will  afford  30  per 
cent,  better  service  than  can  be  obtained  from  a  riser  4  by  16 
inches.  In  the  average  house  the  studding  are  set  16 


Fig.  24— Using  Old   Style  Round  Pipes. 

inches  on  centers,  and  if  2  by  4  inch  single  studding  are  used, 
a  riser  3^  by  14  inches  will  be  the  largest  possible  pipe  that 
can  be  installed. 


38  HEATING  EQUIPMENT 

The  new  type  of  side  wall  register  has  offered  an  improvement 
in  the  method  of  supplying  a  first  floor  register  and  a  riser  from 
the  same  hot  air  pipe.  Of  this  register  we  shall  speak  later. 
Of  the  boot,  one  type  of  which  is  illustrated  in  Fig.  25  we  wish 
to  say,  that,  after  allowing  the  full  width  of  the  studding,  the 


Fig.  25— Bo'ot  for  New  Type  of  Side  Wall  Register. 

space  usually  occupied  by  lath,  plaster  and  baseboard,  together 
with  about  2  inches  of  the  floor,  we  can  still  use  a  riser  7  inches 
deep,  which,  when  properly  baffled,  has  the  capacity  to  supply 
both  register  and  riser. 


Fig.  26 — Arrangement  Causing  Back  Pressure  and  Friction. 

On  much  of  the  cheap  furnace  work  we  find  the  riser  extend- 
ing below  the  cellar  joists  and  the  warm  air  or  leader  pipe  con- 
nected to  it  at  right  angles  as  illustrated  in  Fig.  26  a  practice 


HEATING  EQUIPMENT 


39 


causing  back  pressure  and  friction.     A  homely  illustration  of 
this  may  be  witnessed  by  turning  the  nozzle  of  a  garden  hose 


Fig.  27 — Side  Wall  Register  with  Proper  Boot  and  Double  Pipe. 

directly  against  a  flat  board  first,  and  then  setting  the  board  at 
an  angle  of,  say,  45  degrees.  Note  the  difference  in  the  flow 
of  the  water  from  the  hose  as  it  strikes  the  board.  There  is 
but  one  application  proven  by  the  experiment — transition  boots 
are  valuable,  too  valuable,  in  fact,  to  be  dispensed  with. 

All  risers  of  single  pipe  construction  should  be  thoroughly 
covered  with  asbestos  paper.  Better  than  this,  however,  is  the 
double  pipe  illustrated  by  Fig.  27  which  also  shows  the  installa- 


4O  HEATING  EQUIPMENT 

tion  of  a  side  wall  register  and  a  proper  type  of  boot  for  leader 
connection. 

As  to  the  size  of  the  warm  air  or  leader  pipes,  it  does  not 
seem  necessary  to  write  much,  as  the  sizes  of  such  pipes,  and 
also  the  fact  that  they  should  be  as  direct  and  as  short  as  possible, 
are  well  established  and  generally  known  to  most  furnace  men. 
No  leader  should  be  less  than  8  inches  in  diameter.  First  floor 
rooms,  12  by  12  feet  to  16  by  16  feet,  or  similar  in  area,  should 
have  9-inch  leader  pipes.  For  second  floor  rooms  of  equal  size 
8-inch  leaders  are  sufficient.  First  floor  rooms  having  an  area 
equal  to  from  17  by  17  feet  to  21  by  21  feet  should  have  10- 
inch  leaders.  Same  size  second  floor  rooms,  9-inch  leaders 
First  floor  rooms  22  by  22  feet  to  28  by  28  feet  should  be  sup- 
plied with  12-inch  leaders,  and  for  second  floor  rooms  of  similar 
size  lo-inch  leaders  should  be  provided.  Rooms  in  excess  of 
this  size  had  best  be  supplied  by  two  registers  and  separate  leader 
pipes.  The  above  schedule  is  based  on  lo-foot  ceilings  for  first 
and  9-foot  ceilings  for  second  floor.  For  extreme  exposures 
or  an  abnormal  amount  of  glass  surface  15  to  25  per  cent,  should 
be  added  to  the  above  areas  according  to  circumstances. 

In  general  the  risers  to  second  or  third  floor  rooms  may  be 
25  per  cent,  smaller  than  those  for  the  first  floor,  as  the  velocity 
of  air  in  a  verticle  pipe  is  approximately  25  per  cent,  greater 
than  in  a  horizontal  one. 

The  character  of  the  construction  of  the  building  should  be 
carefully  considered  in  determining  the  size  of  any  part  of  a 
hot  air  heating  system.  The  infiltration  of  cold  air  around  loose 
windows  and  doors,  and  the  loss  of  heat  through  poorly  con- 
structed walls,  should  have  an  influence  when  determining  sizes, 
and  the  delivery  of  a  surplus  amount  of  air  at  a  correspondingly 
lower  temperature  to  the  various  rooms  means  economy  in  the 
consumption  of  fuel  and  longer  life  for  the  apparatus. 

Size  and  Location  of  Registers 

The  proper  locating  of  the  registers  on  a  job  of  warm  air 
heating  has  much  to  do  with  the  perfect  distribution  and  the 
free  circulation  or  passage  of  the  air — conditions  which  contribute 
so  largely  to  the  successful  operation  of  the  system.  Improper 
location  and  incorrect  size  of  registers  insure  partial  if  not  total 
failure. 

Registers  will  allow  of  a  discharge  of  air  equal  to  the  full 
amount  of  the  net  air  capacity  only  when  situated  along  or  in 
the  inner  wall  of  the  room  in  which  they  are  placed.  Fig  28 
shows  a  small  floor  plan,  the  dotted  lines  indicating  the  exposed 
portion  of  the  room,  which  is  that  outside  these  dotted  lines. 
The  warm  air  registers  may  properly  be  located  at  any  point  on 


HEATING  EQUIPMENT  41 

the  inside  of  the  lines  for  good  service.  However,  there  are 
some  conditions  which  a  wise  judgment  on  the  part  of  the  furnace 
man  will  caution  him  to  note  and  provide  for.  One  such  condi- 
tion is  the  placing  of  a  register  as  far  as  possible  toward  the 
north  and  west  on  the  inside  of  a  room,  as  warm  air  can  be 
delivered  toward  the  north  more  easily  through  a  basement 


Fig.  28 — Plan  Showing  Location  of  Registers. 


leader  pipe  than  it  can  be  circulated  toward  the  north  in  the 
room  itself.  The  location  of  the  registers  on  Fig.  28  illustrates 
this  principle. 

The  register  in  a  staircase  hall  which  opens  into  the  second 
or  third  floor  halls  should  be  placed  about  six  feet  from  the  floor 
in  the  side  wall,  the  circulating  register  being  located  in  the 
floor  at  a  point  immediately  below  the  warm  air  register. 

Where  a  long  room  is  exposed  on  either  end,  such  as  a  parlor 


42 


HEATING  EQUIPMENT 


in  a  city-built  house,  or  a  house  erected  in  a  solid  block,  the 
registers  may  be  located  at  each  end  of  the  mantel,  as  shown 
by  Fig.  29. 


Fig.   29 — Location   of   Risers   in    City   Building. 


The  risers  may  be  built,  in  the  brickwork  or,  if  necessary, 
they  may  be  encased  in  studding  at  either  end  of  the  chimney 
breast.  This  will  permit  of  the  use  of  round  risers,  which  should 
serve  the  registers  located  about  six  feet  from  the  floor;  and  the 
very  best  results  will  be  obtained  by  setting  them  in  this  manner. 
It  is  well  to  use  two  circulating  registers  located  as  shown  on 
sketch. 

In  figuring  the  capacity  of  registers  it  is  well  to  allow  50  per 
cent,  of  the  fret-work  size.  We  are  aware  of  the  fact  that 
many  manufacturers  claim  to  make  registers  of  which  two-thirds 
the  fret-work  size  is  net  air  capacity,  but  many  of  such  are 
over-rated.  More  errors  of  judgment  are  committed  through 
underestimating  than  through  overestimating  the  size  of  registers. 


HEATING  EQUIPMENT 


43 


The  following  table  is  submitted  as  a  guide  and  is  based  upon 
ordinary  conditions  of  exposure : 


Size  of  room.         Size  of  leader  pipe. 
8x  8  ft.  to    9x12  ft.        8  in.  ist  floor 
Sin.  2nd  floor 
9  in.  ist  floor 

8  in.  2nd  floor 
10  in.  ist  floor 

9  in.  2nd  floor 


10x12  ft.  to  12x14  ft. 
14x16  ft.  to  i6x2oft. 
20x20  ft.  to  20x24  ft. 


12  in.  ist  floor 
10  in.  2nd  floor 


Area  of  riser. 
40  sq.  in. 

48  sq.  in. 
56  sq.  in. 
75  sq.  in. 


Size  of  register. 

8xio  in.  to    8x12  in. 

8x  Sin.  to  Sxio in. 
10x12  in.  to  10x14  in. 

Sxio  in.  to  8x12  in. 
10x14  in-  to  12x14  in- 

8x12  in.  to  10x12  in. 
14x16  in.  to  16x20  in. 
12x14  in.  to  14x16  in. 


CHAPTER  IV 
INSTALLATION  OF  THE  FURNACE 


There  is  something  fascinating  in  the  construction  of  a  first 
class  piece  of  work,  whether  it  be  an  intricate  piece  of  mechanism, 
a  handsome  and  well-appointed  home,  or  a  heating  apparatus 
installed  to  properly  warm  the  same ;  therefore  we  may  well 
say  that  we  have  now  reached  a  highly  interesting  and  attractive 
portion  of  our  discussion  of  progressive  furnace  heating,  namely, 
that  of  considering  the  practical,  as  well  as  the  theoretical,  side 
of  actual  furnace  installation. 

We  shall  aim  to  approach  the  subject  from  the  very  beginning, 
starting  with  the  actual  planning  of  the  heating  apparatus,  and 
for  illustration  will  consider  a  good-sized  suburban  home,  ex- 
posed on  all  points  of  the  compass.  Fig.  30  shows  the  first  floor 
of  the  building,  the  rooms  to  be  warmed  being  the  Parlor,  Living 
Room,  Library,  Dining  Room,  Reception  Hall  and  Rear  Entry. 
Fig.  31  shows  the  second  floor,  consisting  of  a  Den  and  Alcove, 
four  Chambers,  Bath  Room  and  Hall,  making  a  total  of  fourteen 
rooms  to  be  supplied  with  heat. 

The  first  heating  system  we  will  consider  will  be  one  in  which 
no  provision  is  made  for  any  ventilation  further  than  that  or- 
dinarily obtained  from  a  properly  constructed  hot-air  furnace 
installation. 

Assuming  that  a  chimney  flue  of  good  construction  and 
adequate  area  has  been  provided  in  the  proper  location  (as  is 
the  case  for  the  residence  illustrated),  the  first  step  is  to  suitably 
tabulate  the  information  necessary  to  enable  the  construction 
data  to  be  figured.  We  refer  by  this  to  the  size  and  location  of 
the  various  rooms,  the  number  and  size  of  windows  (glass 
area),  counting  outside  doors  as  glass  surface,  and  the  amount 
or  area  of  all  outside  exposed  wall  for  each  room.  As  we  have 
stated  before  in  these  articles,  the  only  correct  method  for  de- 
termining furnace  capacity  involves  a  consideration  of  the  vari- 
ous cooling  surfaces  of  a  room  or  building. 


FURNACE  INSTALLATION 


45 


i'ig.  30 — First  Floor  Plan,  Giving  Square  Feet  of  Wall  and  Glass  Exposure 


FURNACE  INSTALLATION 


ALCOVC 

s'-o'sd'-O" 
Wail  Exp.   90?  II 
Glass    •      36?    j  | 

i  i 


Fig.  31— Second  Floor  Plan,  Giving  Square  Feet  of  Wall  and 
Glass  Exposure. 


FURNACE  INSTALLATION  47 

This  tabulated  information   follows,  and   for  convenience  all 
rooms  are  numbered. 

Sq.  ft.  of 

Cubic  Sq.  ft.  of  ex-  exposed 

•Room.  Size.  feet.  posed  glass.  wall. 

No.  i       Parlor    14/9x14'  xii'  2,244  60' N.  &  W.  316 

'    2      Living    room...  15'  XIS'QXII'  2,607  57' N.  &  E.  338 

'     3      Library    I5'3xi3'9xii'  2,310  48' S.  &  E.  319 

'    4      Dining  room...  15'  XIQ'  xii'  3,135  60' W.  374 

'    5      Reception   hall..  9'  x25'6xii'  2,519  24' N.  (^)  None 

'    6      Rear,  entrance. .  4'  xio'6xii'  462  18'  E.  132 

:    7      Den 14'  xis'  xio'  2,100  60'  N.  &  W.  290 

'    8      Alcove   9'  x  9'  xio'  810  36'  N.  90 

'    9      Chamber    14'  xis'6xio'  2,170  60'  N.  &  E,  295 

"  10      Guest  room 12'  xis'  xio'  1,800  48' S.  &  E.  270 

"  ii       Chamber    12'  xis'6xio'  1,860  42' W.  156 

"  12      Bath  room 7'9x  8'6xio'  650      18' W.  75 

"  13      Chamber    11'  xi3'9xio'  1,520  54'  S.  E.  &  W.  355 

"  14      Hall 9'  X25'  xio'  2,200  24' S.  120 

NOTE. — Glass  exposure  of  hall,  first  floor,  estimated  at  one-half 
actual   figures.     Measurement  into  bay-window  taken   for   dining  room. 

When  estimating  pipe  sizes,  area  of  flues  and  registers  re- 
quired, and  the  size  of  furnace  necessary  to  properly  handle 
the  work,  we  have  many  rules  to  select  from  to  guide  us  in 
the  calculations.  One  authority  states  that  the  size  of  air  pipes 
for  the  first  floor  rooms  may  be  obtained  by  dividing  the  out- 
side wall  surface  of  each  room  by  3,  the  result  giving  the  proper 
cross-sectional  area  in  square  inches  of  the  desired  air  pipe.  For 
the  second  floor  take  5  as  the  divisor,  and  for  the  third  floor  6, 
using  always  the  pipe  having  an  area  next  larger  than  that  given 
by  the  computation.  To  illustrate,  the  size  obtained  by  rule 
might  be  74  square  inches ;  therefore  the  next  larger  size  of  pipe 
would  be  78  square  inches,  or  one  10"  in  diameter. 

For  rooms  having  an  excessive  amount  of  glass  surface  the 
area  of  the  air  pipe  should  be  increased  twenty-five  per  cent., 
and  those  having  a  northern  and  western  exposure  should  have 
increased  sizes  of  supply  pipes. 

This  rule  is  based  upon  the  fact  that  in  the  average  type  of 
building,  the  windows  and  outside  doors  (total  glass  surface) 
amount  to  practically  one-sixth  of  the  total  exposed  wall  sur- 
face, and,  further,  it  is  estimated  that  four  square  feet  of  ex- 
posed wall  surface  is  equivalent  to  one  square  foot  of  exposed 
glass  surface. 

While  an  application  of  the  above  rule  leaves  much  to  the 
good  judgment  of  the  furnace  man,  it  is  the  beginning  of  a 
practical  method  for  recognizing  the  difference  in  the  cooling 
surfaces  of  a  room,  and  it  furnishes  great  improvement  over 
the  "hit-or-miss"  methods  so  commonly  used. 


48  FURNACE  INSTALLATION 

Those  who  consider  the  heat  unit  in  estimating  capacities; 
figure  that  one  square  foot  of  an  ordinary  brick  wall  will  trans- 
mit or  lose  1 6  heat  units  per  hour,  and  that  each  square  foot 
of  glass  surface  will  lose  heat  at  the  rate  of  85  heat  units  per 
hour,  these  ratios  being  based  on  zero  weather  outside  and  an 
inside  temperature  of  70  degrees.  Multiplying  the  total  exposed 
wall  surface  by  16,  the  total  glass  surface  by  85,  and  adding  the 
products,  will  give  the  total  hourly  heat  loss.  For  the  first  floor, 
multiply  this  result  by  0.0094  to  obtain  the  cross-sectional  area 
in  square  inches  of  the  warm  air  pipe.  For  the  second  floor  the 
multiplier  is  0.0047. 

These  multipliers  are  obtained  as  follows:  The  heat  trans- 
mission which  must  be  offset  by  the  air  supply  is  based  on  de- 
livering the  air  into  the  rooms  at  140  degrees  in  zero  weather 
and  allowing  this  air  to  cool  to  70  degrees  before  it  escapes.  If, 
the  air  supply  were  only  cooled  one  degree  to  give  up  the  amount 
of  heat  necessary  there  would  be  fifty-five  times  as  many  cubic 
feet  of  air  required  in  an  hour  as  there  are  heat  units  lost  in 
transmission,  since  fifty-five  cubic  feet  of  air  cooling  one  degree 
will  only  give  up  one  heat  unit.  As,  however,  each  cubic  foot 
of  air  is  to  be  cooled  70  degrees,  the  amount  of  air  needed  in 
an  hour  is  obtained  by  taking  55/7oths  of  the  number  of  heat 
units.  As  this  is  the  number  of  cubic  feet  of  air  per  hour, 
dividing  by  60  will  give  the  cubic  feet  per  minute.  In  the  first 
floor  rooms  the  velocity  which  air  will  get  in  a  furnace  heating 
system,  due  to  the  height  of  the  first  floor  registers  above  the  hot 
zone  of  the  furnace,  is  about  200  feet  per  minute.  Dividing 
the  total  amount  of  air  needed  in  a  minute  for  heating  the  room 
by  the  velocity  \vith  which  this  air  will  flow,  will  give  the  num- 
ber of  square  feet  of  area  in  the  pipe  needed  to  conduct  the 
required  amount  of  air.  Multiplying  this  result  by  144  gives 
the  area  of  the  pipe  in  square  inches.  Expressed  numerically 
the  operation  is :  Heat  units  X  55  X  144  -r-  70  -r-  60  -f-  200  = 
heat  units  X  0.0094.  If  for  second  story  rooms  400  feet  velocity 
is  allowed,  as  such  velocity  can  be  attained,  the  multiplier  for 
the  number  of  heat  units  becomes  0.0047. 

The  above  are  a  few  of  the  rules  for  determining  capacities 
and  pipe  sizes,  and  we  would  say  in  this  connection  that  any 
rule  that  properly  takes  into  consideration  the  cooling  surfaces 
of  a  building  may  be  used  with  safety. 

We  like  very  much  Mr.  Prizer's  rule  for  estimating  the  capacity 
of  furnace  required,  and  his  method  of  determining  the  sizes  of 
warm  air  pipes.  Taking  into  consideration  the  cubic  feet  of  air 
space,  of  exposed  wall  surface,  and  of  exposed  glass  surface, 
Mr.  Prizer  reduces  the  cooling  surface  of  each  room,  to  an 
amount  which  he  calls  "Equivalent  Cubic  Feet." 


FURNACE  INSTALLATION  49 

The  rule  is  as  follows:  Taking  the  actual  cubic  feet  of  space 
in  a  room  as  a  basis,  add  75  cubic  feet  for  each  square  feet  of 
exposed  glass  surface,  and  8  cubic  feet  for  each  square  foot  of 
exposed  wall  surface.  The  provision  for  exposure  is  covered 
by  adding  ten  per  cent,  to  the  glass  and  wall  surface  for  a 
northern  or  western  exposure,  and  deducting  ten  per  cent,  from 
the  exposed  glass  and  wall  surface  for  a  southern  and  eastern 
exposure.  All  outside  doors,  of  course,  are  figured  as  glass 
surface,  the  same  as  with  other  rules.  Should  storm  doors  be 
provided,  or  double  doors,  those  outside  are  then  counted  as 
exposed  wall  surface. 

Adding  together  the  totals  thus  obtained  will  give  the  Equiva- 
lent Cubic  Feet  of  space  to  be  warmed.  The  entire  space  in 
halls,  provided  the  first  floor  hall  opens  into  the  second  or  possibly 
the  third  floor  as  well,  is  considered  in  figuring  the  size  of  pipe, 
etc.,  for  the  first  floor  hall.  This  rule,  of  course,  is  useful  only 
when  regarded  in  connection  with  tables  giving  the  area  of 
pipes  and  ducts  for  use  with  Equivalent  Cubic  Feet  and  with 
furnaces  rated  to  take  care  of  a  certain  amount  of  Equivalent 
Cubic  Feet.  However,  it  furnishes  an  exact  basis  on  which  to 
work  and  we  consider  it  a  very  good  and  pronounced  advance 
in  the  methods  of  estimating  furnace  work. 

The  illustrations  included  show  tne  sizes  of  windows  and  doors 
and  size  of  rooms,  and  we  shall  consider  the  same  floor  plans, 
giving  data  as  to  sizes  of  pipes,  sizes  and  locations  of  regis- 
ters, etc. 

To  determine  the  proper  size  of  furnace  for  this  work,  we 
may  use  in  our  calculations  any  one  of  a  number  of  rules.  For 
instance,  it  is  generally  recognized  that  one  square  foot  of  grate 
area  in  a  furnace  will  properly  care  for  5,000  cubic  feet  of  space 
in  the  average  dwelling.  Using  this  rule  in  determining  the 
size  of  furnace  required,  we  figure  the  total  cubic  space  to  be 
warmed  in  the  residence  illustrated,  as  being  a  little  more  than 
26,000  cubic  feet,  and  dividing  this  amount  by  5,000,  show 
that  a  furnace  having  5  1/5  square  feet  of  grate  is  required, 
or  one  with  an  area  of  approximately  750  square  inches.  A 
circular  grate,  31  inches  in  diameter,  conforms  to  this  require- 
ment. This  rule,  we  may  say,  is  based  upon  the  most  extreme 
climatic  conditions  prevailing  and  for  locations  where  the 
thermometer  reaches  from  10  to  20  degrees  below  zero. 

A  preferred  rule  and  one  which  may  be  applied  with  safety 
is  to  determine  the  total  amount  of  glass  surface  in  the  rooms 
to  be  heated  and  the  total  net  exposed  wall  surface.  It  is  cor- 
rectly estimated  that  I  square  foot  of  grate  in  a  furnace  is 
capable  of  taking  care  of  300  square  feet  of  glass  surface  or  its 


50  FURNACE  INSTALLATION 

equivalent,  4  square  feet  of  exposed  wall  surface  being  considered 
the  equivalent  of  i  square  foot  of  glass. 

Considering  now  the  residence  illustrated,  we  find  a  total  glass 
surface  of  a  little  more  than  600  square  feet.  The  total  exposed 
wall  surface  is  3,130  square  feet,  and  after  deducting  the  glass 
area  from  this  total  amount,  we  have  a  net  exposed  wall  surface 
of  about  2,500  square  feet.  Reducing  this  net  amount  to  its 
equivalent  in  glass  surface  by  dividing  by  4,  on  the  basis  men- 
tioned, gives  a  product  of  630  square  feet  of  equivalent  glass, 
which,  added  to  the  actual  glass  surface,  690  square  feet,  makes 
the  total  1,239  square  feet  of  glass. 

Now,  applying  the  rule  just  given,  we  divide  this  sum  by  300, 
and  learn  from  the  result  that  a  furnace  having  a  little  more 
than  4  square  feet  of  grate  surface  would  probably  do  the  work. 
Other  formulas  used  in  like  manner  show  that  a  furnace  with 
from  4  to  5^2  square  feet  of  grate  surface  would  be  the  size 
necessary  for  this  requirement. 

No  person  without  experience  is  capable  of  applying  any 
one  of  the  rules  with  precision.  The  judgment  of  an  experienced 
man  increases  the  value  of  all  rules,  hence  by  using  them  in  ac- 
cordance with  what  his  better  knowledge  of  the  conditions  sur- 
rounding the  work  teaches  him,  the  result  will  be  more  in  keep- 
ing with  that  obtained  by  practical  experience.  In  our  opinion 
for  this  work  a  furnace  should  be  placed  which  has  a  grate 
area  of  about  700  square  inches,  which  would  mean  a  3O-inch 
grate. 

When  working  out  the  estimate  for  the  sizes  of  the  warm  air 
pipes  in  the  cellar,  the  same  discrepancy  is  found  when  applying 
miscellaneous  rules  as  is  noted  when  determining  the  size  of  the 
furnace.  Good  judgment  based  upon  practical  experience  de- 
mands that  no  warm  air  leader  pipe  in  the  basement  should  be 
smaller  than  7  inches  in  diameter,  no  matter  what  the  size  of 
the  connection  may  be. 

Given  herewith  is  a  schedule  showing  the  sizes  of  warm  air 
cellar  pipes,  of  vertical  flues,  and  of  registers  required  for  this 
residence,  and  in  this  connection  attention  should  be  called  to 
the  fact  that  every  register  and  vertical  flue  is  supplied  by  a 
separate  warm  air  pipe,  with  the  exception  of  the  library  and 
the  guest  chamber  above. 

A  baseboard  register  is  planned  for  the  library,  while  a  com- 
bination vertical  flue,  supplied  by  a  1 3-inch  warm  air  leader, 
serves  the  library  and  guest  room  over  it.  The  character  of  this 
flue  and  the  position  of  the  register  are  indicated  in  Fig.  27. 


FURNACE  INSTALLATION 


Fig.  32— First  Floor  Plan,  Showing  Sizes  of  Flues  and  Registers. 


52  FURNACE  INSTALLATION 

Fig.  32  shows  a  plan  of  the  first  and  Fig.  33  a  plan  of  the 
second  floor.  The  sizes  of  all  registers  and  hot  air  flues  are 
given,  together  with  their  locations. 

The  fireplaces  in  the  parlor  and  living  room  prove  to  be  natural 
ventilators  for  these  rooms. 

Size  of  warm  air  Size  of  Size  of 

Room.                          cellar  pipe.  vertical  flue.  register. 

Parlor    n  6^x14  12x14 

Living  Room 10^2  6    xi5  10x13 

Library    13  7     xi5  10x12 

Dining  Room n  6^x14  12x14 

Reception  Hall II  6^x14  12x16 

Rear  Entrance 7  3J^x  8  6x  8 

Den    7J£  3j^xi  I  8xio 

Alcove   7  3^x  8  6x  8 

Chamber 4     xi2*^  10x10 

Guest  Room  (See  Library)  3/^xn  8xio 

Chamber    8  4     xi2^  10x10 

Bath  Room 7  3^x  8  6x  8 

Chamber    7^4  4     xi2^2  loxio 

Hall (Included  with  first  floor) 

Arrangement  is  made  to  recirculate  the  inside  air  from  the 
lower  floor.  A  30"  X  30"  circulating  register  is  set  in  the  panel- 
ing of  the  main  stairway,  this  register  opening  into  a  chamber 
24"  X  36",  located  under  the  stairs.  Connecting  with  this 
chamber  is  a  i6"X  30"  duct,  which  is  carried  along  the  ceil- 
ing of  the  basement  to  that  certain  point,  where  a  vertical  drop 
to  the  floor  of  the  basement  can  be  made  without  interfering 
with  the  passage-way  or  piping.  At  such  particular  point  the 
drop  is  made  and  the  duct  then  connected  into  the  cold  air  pit 
of  the  furnace  at  the  side  opposite  to  that  from  which  the  cold 
outside  air  enters  the  pot.  This  duct  is  provided  with  a  damper. 

Fig.  34  shows  a  plan  of  the  basement  and  illustrates  the  man- 
ner of  locating  the  furnace  and  of  installing  the  piping.  The 
sizes  of  all  leaders  are  marked,  and  also  the  location  and  size 
of  the  circulating  duct,  the  cold  air  chamber,  the  cold  air  duct, 
and  the  smoke  connection. 

The  cold  air  or  filtering  chamber  is  3'  X  4'  6"  in  size,  and  is 
provided  with  baffles  on  which  cheese  cloth  is  stretched  sufficient 
to  cover  about  two-  thirds  of  each  bafflle,  all  of  which  are  remov- 
able for  cleaning.  The  sash  of  the  window  is  hinged  at  the  top 
and  a  chain  connecting  to  it  is  run  to  a  convenient  point  outside 
of  the  cold  air  chamber,  by  means  of  which  the  supply  of  cold 


FURNACE  INSTALLATION 


Fig.  33 — Second  Floor  Plan,  Showing  Sizes  of  Flues  and  Registers. 


54 


FURNACE  INSTALLATION 


Fig.  34 — Basement  Plan,  Showing  Method  of  Locating  Furnace  and  Piping 


FURNACE  INSTALLATION 


55 


air  is  controlled.  Fig.  35  shows  a  sectional  view  of  this  cham- 
ber with  the  cold  air  duct  leading  from  it.  This  duct  is  14"  X 
36"  in  size,  and  built  of  cement  with  an  arched  cement  top. 

The  installation  of  an  apparatus  as  here  described  will  cost 
double  the  amount  usually  paid  for  the  cheap  work  ordinarily 
placed.  The  owner,  however,  will  have  the  desired  satisfaction 
of  being  able  to  thoroughly  warm  the  house,  regardless  of  the 
condition  of  the  weather  or  the  direction  of  the  wind. 


Fig.  35 — Sectional  View  of  Filtering  Chamber. 

A  few  general  directions  for  the  installation  in  question  should 
be  given,  as  follows: 

Place  dampers  in  all  leaders,  except  that  feeding  the  reception 
hall. 

Connect  all  dampers  with  chains  running  to  a  switchboard  or 
chain  plate,  located  in  rear  entrance  of  first  floor,  or  at  some 
other  point  equally  convenient. 

Thoroughly  cover  all  basement  piping  with  heavy  asbestos 
paper. 


56  FURNACE  INSTALLATION 

Make  use  of  anti-friction  connections  in  joining  leaders  to 
vertical  air  flues.  This  style  costs  more,  but  is  worth  more  than 
it  costs. 

Give  a  good  pitch  to  all  leaders,  as  air  will  not  travel  through 
a  horizontal  pipe  without  friction. 

Many  other  minor  directions  might  be  included.  However, 
the  furnace  man  accustomed  to  superior  work  will  recognize  in 
the  data  supplied  all  that  is  required  to  cover  a  good  job. 


CHAPTER  V 
TRUNK  LINE  AND  FAN-BLAST  HOT  AIR  HEATING 


Every  one  identified  with  furnace  heating  understands,  we 
believe,  that  more  friction  prevails  in  conveying  air  or  water 
through  several  small  pipes  than  when  combining  the  same  vol- 
ume and  carrying  it  through  one  or  more  larger  pipes.  With 
plenty  of  headroom  in  the  basement  the  pipes  may  be  made 
round;  under  other  conditions  they  should  be  rectangular  in 
shape. 

In  starting  to  lay  out  a  trunk  line  job  the  designer  of  the 
system  should  keep  in  mind  the  following  rules  and  plan 
accordingly : 

(a)  A  single  pipe  feeding  two  or  more  smaller  ones  must  have 
an  area  equal  to  the  combined  area  of  all  pipes  supplied  by  it. 
See  Fig.  36. 


Fig.  36 — Plan  of  Trunk  Line. 


(b)  In  order  to  eliminate  the  friction  due  to  choking  and  the 
presence  of  pockets,  the  top  line  of  all  piping  should  be  straight ; 
therefore  any  "drawing  in"  or  reduction  of  the  piping  must  be 
made  at  the  sides  and  bottom.     Fig.  37  illustrates  this  condition. 

(c)  A  certain  pitch  of  the  piping  having  been  established  it 
should  be  continued  from  the  furnace  to  the  last  register  or  riser 
supplied. 

(d)  Do  not  make  reductions  too  quickly.     Often  a  single  reg- 
ister supplied  will  not  change  the  size  of  the  main  service  pipe, 
and  such  connections,  when  near  the  furnace,  should  be  taken 


58  TRUNK  LINE  HEATING 

from  the  side  of  the  trunk  line  at  the  bottom  line  of  the  pipe,  as 
illustrated  by  Fig.  38. 

(e)  Branches,  if  of  considerable  length,  may  be  run  from  the 
top  of  the  trunk  line,  and  where  the  construction  of  the  building 
permits,  the  branch  may  be  carried  between  joists  as  indicated 
by  Fig-  39- 

These  include  the  most  essential  points  considered  in  laying 
out  the  piping  of  a  trunk  line  system,  and  although  practically 


Fig.  37 — Elevation  of  Trunk  Line. 

every  job  presents  new  difficulties  necessary  to  meet  and  over- 
come, the  rules  herein  submitted  form  a  safe  starting  point  in 
developing  the  system  of  piping. 


\     ^Damper 


BRANCH 


Fig.  39 — Connection   Carried   Between   Joists. 

Select  a  furnace  of  generous  size  for  the  work,  one  having 
an  area  for  the  passage  of  air  of  from  40  to  50  per  cent,  greater 
than  the  area  of  the  trunk  lines.  Work  of  this  character  is  not 
cheap  and  if  the  furnace  man  is  considering  a  low  or  even  mod- 
erate priced  installation  he  must  not  figure  on  a  trunk  line  system. 
But  if  the  best  is  to  be  selected  with  a  view  to  procuring  durabili- 
ty, or  length  of  service  without  repairs,  as  well  as  comfort  and 
satisfaction  from  the  use  of  the  apparatus,  such  a  system  prop- 
erly installed  will  suitably  answer  every  requirement.  In  this 
age  of  specializing,  trunk  line  heating  may  be  properly  regarded 
as  a  specialty  requiring  the  attention  of  specialists,  and  of  your 
best  workmen  none  are  too  skillful  for  such  work. 

When  necessary  to  change  direction  with  a  trunk  line,  do  not 
make  an  abrupt  turn  at  right  angles;  rather  turn  with  a  long 
sweep  in  order  that  the  air  can  move  in  the  new  direction  with- 
out any  considerable  friction. 

It  is  usually  the  case  that  two  or  three  registers  or  risers  are 
supplied  by  the  trunk  line  at  or  near  to  the  end  of  it  and  that 


TRUNK  LINE  HEATING 


59 


two  or  three  branches  lead  from  it  between  the  furnace  and  the 
extreme  end.  With  round  piping  these  branches  should  be  taken 
from  the  tapering  sleeve,  reducing  the  size  of  the  trunk  line. 
When  rectangular  piping  is  used  (and  this  style  is  preferable), 
take  the  branches  from  the  side  of  the  pipe  at  the  bottom,  as 
the  air  in  passing  through  hugs  the  top,  seeking  the  first  outlet. 


Fig.  38 — Connection  Taken  from  Side  of  Trunk  Line. 

Fig.  40  will  show  clearly  the  reason  for  this  and  illustrates  how 
and  why  the  connection  of  a  branch  does  not  interfere  with  the 
hottest  air  traveling  along  the  upper  side  of  the  trunk  line  to 
its  extreme  end. 


Openings  for  Branches  • 
Fig.  40 — Rectangular  Trunk  Line,  Showing  Out  for  Branches 
and  Method  of  Reducing  Area. 

Secure  the  trunk  lines  firmly  in  place  by  straps  of  light  band 
iron  screwed  or  nailed  to  joists.  A  quarter  turn  in  each  vertical 
upright  will  afford  a  good  appearance  to  the  hanger  and  per- 
mit it  to  fit  snugly  against  the  joist.  Fig.  41  gives  an  outline  of 
the  method  for  its  use. 


Fig.  41 — Method  of  Supporting  Trunk  Line. 

The  furnace  man  who  wishes  to  construct  a  job  that  will  surely 
please  and  delight  his  customer,  as  well  as  prove  a  source  of 
great  satisfaction  to  himself,  will  do  well  to  try  out  this  system 


60  TRUNK  LINE  HEATING 

on  the  next  installation  of  good  size,  when  we  predict  he  will 
become  a  convert  to  the  principle  of  moving  air  in  large  volumes 
and  ever  after  remain  a  stanch  advocate  of  the  idea.  Air  cools 
quickly  in  small  pipes,  and  consequently  must  be  heated  to  a 
higher  temperature  than  when  otherwise  carried. 

Suppose  a  furnace  job  erected  by  the  regular  method  requires 
two  10",  two  n",  three  8"  and  one  12"  pipes.  Their  combined 
area  would  be  600  sq.  in.  and  the  total  circumference  approx- 
imately 254.5  inches.  If  a  single  trunk  line  could  be  substituted 
a  28"  pipe  with  an  area  of  615.7  SQ-  m-  would  be  needed.  The 
circumference  of  a  28"  pipe  is  88  inches,  and  therefore  the 
cooling  surface  in  the  small  piping  is  nearly  three  times  that  in 
the  one  28"  trunk  line. 

The  brainy  successful  furnace  man,  ever  on  the  lookout  for 
ideas  and  methods  that  will  enable  him  to  do  better  work,  finds 
much  food  for  thought  and  study  when  considering  the  trunk 
line  system  of  furnace  piping.  Those  who  never  attempt  to  rise 
above  the  old  tried  out,  and  often  worn  out,  methods  of  doing 
a  certain  line  of  work  never  advance  farther  than  to  obtain  pos- 
sibly the  name  and  reputation  of  good  all  around  workmen. 

While  not  believing  in  the  right  of  the  furnace  man  to  experi- 
ment at  the  expense  of  a  customer,  there  are  certain  theories, 
methods  and  suggestions  which  must  necessarily  be  tried  out 
in  actual  practice  if  we  are  to  progress  in  our  business,  and 
there  is  no  house  owner  but  wants  the  best  character  of  heating 
apparatus  if  obtainable  at  a  price  within  his  means.  This  can 
signify  but  one  thing  to  the  furnace  man:  He  must  (as  he 
should)  accept  the  full  responsibility  for  his  work,  guaranteeing 
to  make  any  changes  necessary  to  the  complete  fulfillment  of 
his  agreement  with  the  owner. 

The  same  care  in  the  proper  installation  of  the  furnace,  size 
of  same,  and  method  of  introducing  fresh  air  and  exhausting 
the  foul,  is  as  essential  for  the  trunk  line  system  as  for  the 
regular  system  of  piping,  to  insure  a  successful  working  job. 

A  method  of  running  furnace  pipes,  which  has  been  styled 
the  "trunk  line  system,"  finds  much  favor  among  furnace  men 
in  certain  localities.  However,  in  other  parts  of  the  country  it 
is  little  known  or  adopted,  probably  because  a  considerable 
amount  of  study  and  care  need  be  exercised  in  its  installation 
if  good  results  are  to  be  obtained  from  its  use.  The  system 
covers  a  simple  positive  method  of  conveying  air  to  the  various 
stacks  and  registers  of  a  furnace  heating  system. 

When  planning  for  the  installation  of  the  trunk  line  system 
the  sizes  of  furnace,  stacks,  registers  and  cold  air  supply  remain 
the  same  as  for  the  regular  method,  the  only  difference  between 
the  two  systems  lying  in  the  manner  of  running  the  basement 
pipes. 


FAN  BLAST 


Fan  Blast  Hot  Air  Heating 


61 


In  discussing  the  subject  of  warm  air  heating  and  the  pos- 
sibility of  apparatus  for  such  purpose,  we  have  thus  far  con- 
sidered only  those  systems  which  circulate  the  air  by  reason  of 
the  difference  in  the  specific  gravity  or  weight  of  the  warmed 
cr  expanded  air,  and  that  of  the  denser  cold  air  admitted  through 
the  cold  air  duct. 

In  localities  where  electric  current  is  available  for  power,  an 
electrically  operated  and  controlled  fan  may  be  employed  to 
good  advantage  in  connection  with  the  furnace.  It  is  possible 
with  the  use  of  a  fan  as  an  auxiliary  to  the  heating  apparatus 
to  change  the  air  frequently  and  positively,  no  matter  what  may 
be  the  direction  or  velocity  of  the  wind  or  the  location  (as  to 
exposure)  of  the  rooms  to  be  warmed. 


Fig.  42 — Diagram  of  Arrangement  for  Exhaust  System. 


A  system  of  this  kind  would  be  called  a  "mechanical  system," 
"fan-blast  system"  or  a  "warm  air  fan  system,"  and  is  particularly 
adaptable  when  employed  to  ventilate  buildings  in  which  many 
people  congregate,  such  as  a  church,  school  or  public  hall,  and 
also  for  large  residences  of  the  modern  type. 

Some  of  the  larger  residences  of  this  class  could  not  be 
warmed  with  an  ordinary  hot  air  system  except  by  the  installa- 
tion of  two  or  more  furnaces,  each  located  in  different  sections 
of  the  building,  while  with  a  fan-blast  hot  air  apparatus  the  fur- 
naces (if  more  than  one  be  necessary)  may  be  located  at  some 
central  and  convenient  point  in  the  basement,  and  the  trunk  line 


62 


FAN  BLAST 


method  of  piping,  as  described  in  a  recent  article,  used  to  con- 
vey the  heated  air  to  the  several  risers  or  stacks.  Warm  air 
ducts  when  few  in  number  not  only  present  a  neat  appearance, 
but  are  greatly  to  be  desired  when  the  efficiency  of  the  installa- 
tion is  to  be  considered. 

Should  a  fan  be  employed  in  connection  with  a  heating  and 
ventilating  system,  either  one  of  two  methods  may  be  adopted. 
They  are  known  as  the  exhaust  and  the  plenum  methods,  and 
are  separate  and  distinct  from  each  other  in  the  manner  of  in- 
stallation and  operation.  The  exhaust  method,  which  is  il- 
lustrated by  Fig.  42,  is  installed  as  follows: 


Air  Motor  and 

Screens     Moistening          Fan  •* 


Fig.  43 — Arrangement   for   Plenum   System   Shown  in   Plan. 


The  furnace  is  located  in  the  usual  manner  and  place.  The 
cold  air  is  admitted  to  the  furnace  in  the  usual  manner  through 
a  cold  air  duct  connecting  with  a  pit  under  the  furnace,  and  is 
drawn  upward  over  the  heated  surfaces  of  the  furnace,  warmed, 
and  conveyed  to  the  several  rooms  through  air  ducts  and  registers. 
The  foul  or  impure  air  is  exhausted  from  each  room  through  a 
foul  air  register  connecting  with  a  foul  air  duct.  These  ducts 
extend  to  the  attic  of  the  building,  where  an  exhaust  fan  of 
sufficient  size  is  located  which  propels  or  drives  this  air  from 
the  building  through  an  opening  in  the  wall  or  through  roof 
ventilators.  In  other  words,  the  fan  creates  a  vacuum  which 
pulls  the  pure  warm  air  through  the  building  and  exhausts  it  to 


FAN  BLAST  63 

the  atmosphere,  after  the  heat  conveyed  by  it  has  cooled  and 
the  air  has  become  foul  owing  to  the  respiration  of  the  occupants 
of  the  building,  or  by  other  sources  of  contamination.  The  suc- 
tion produced  by  the  fan  causes  an  infiltration  of  air  through 
crevices  around  doors  and  windows,  the  amount  varying  in 
volume  according  to  the  size  and  speed  of  the  fan. 

The  plenum  method,  as  illustrated  by  Fig.  43  is  the  system  more 
generally  used  in  connection  with  furnace  heating.  In  arrang- 
ing the  apparatus  the  outside  air  is  admitted  through  a  wire  or 
grill  screened  opening  in  the  outside  wall  into  a  chamber  within 
the  basement  of  the  building.  Here  it  may  be  filtered  to  re- 
move dust  and  dirt  and  may  also  be  moistened  if  such  a  condi- 
tion is  desired. 

The  air  then  passes  through  a  duct  to  the  fan,  which  propels 
it  forward  through  the  furnace  and  warm  air  ducts  into  the 
various  rooms  to  be  warmed  and  ventilated. 

The  foul  air  is  exhausted  through  registers  into  ducts  or  flues 
which  extend  upward  through  the  building  to  a  point  well  above 
the  roof. 

With  this  system  in  operation  the  air  leakage  around  out- 
side doors  and  windows  is  outward,  as  the  fan  drives  the  air 
through  the  system  and  into  the  rooms  under  a  slight,  though 
constant,  pressure  and  a  certain  definite  air  change  may  be 
figured  and  secured  whatever  may  be  the  condition  of  the  weather. 

The  ventilation  of  a  building  is  now  considered  by  both  archi- 
tect and  owner  to  be  as  essential  as  the  heating  system,  and  a 
modern  residence  is  not  considered  complete  unless  it  is  well  ven- 
tilated. All  persons  versed  on  the  subject  of  ventilation,  and 
who  are  competent  to  advise,  say  that  there  can  be  no  ventilation 
when  a  building  is  warmed  by  direct  steam  or  hot  water  or  by 
a  furnace  without  a  generous  admission  of  fresh  air  to  the 
building,  and  the  mission  of  the  furnace  has  not  been  fulfilled 
until  this  fresh  air  feature  has  been  provided. 

We  have  met  with  the  argument  that  it  is  expensive  to  burn 
the  fuel  necessary  to  warm  so  large  a  volume  of  fresh  air,  a 
perfectly  true  statement.  To  this  we  may  answer — and  likewise 
the  services  of  a  physician  are  costly,  and  which  is  the  cheaper 
in  the  end:  a  coal  bill  based  upon  the  warming  of  sufficient 
fresh  air  to  insure  healthfulness,  cheerfulness  and  comfort,  or 
a  coal  bill  based  upon  no  ventilation  or  recirculated  air,  with  the 
attendant  consequences  of  ill  health,  doctors'  fees  and  loss  of 
time  from  business,  to  say  nothing  of  the  discomfort  attending 
such  experiences. 

When  a  residence  is  but  sparsely  occupied  (as  the  majority 


64  FAN  BLAST 

of  all  residences  are)  an  air  change  three  times  per  hour  will 
provide  all  of  the  ventilation  necessary,  and  this  rate  of  air 
change  may  be  obtained  with  very  little  increased  expenditure 
for  fuel — provided  the  apparatus  is  properly  arranged — and  it 
may  be  increased  to  five  or  six  changes  per  hour  at  times  when 
the  rooms  are  to  accommodate  an  exceptional  number  of  people, 
as  at  the  time  of  a  social  gathering. 

With  a  fan  furnace  system  installed,  an  air  change  of  five 
times  per  hour  may  be  easily  obtained  without  an  excessive  ex- 
pense for  fuel. 

When  the  building  is  unoccupied,  or  but  sparsely  so,  it  is  not 
necessary  to  use  the  fan,  and  the  expense  of  its  operation  may 
be  saved.  This  is  particularly  true  when  a  system  of  this 
character  is  installed  to  warm  and  ventilate  a  school  building. 
Certainly  it  is  not  necessary  to  operate  the  fan  when  the  rooms 
are  unoccupied,  and  a  school  building  is  occupied  only  six  or 
seven  hours  a  day,  never  more  than  eight  hours. 

All  ventilating  ducts  should  be  provided  with  close  fitting 
dampers  located  above  the  outlet  register.  Within  a  short  time 
after  school  is  dismissed  the  fan  should  stop  running  and  these 
dampers  should  be  closed,  and  remain  closed  until  possibly  eight 
o'clock  the  following  morning  when  the  attendant  should  open 
them  and  put  the  fan  in  operation. 

At  periods  when  the  atmosphere  is  heavy  or  depressing  or 
on  occasions  when  the  building  is  to  be  generally  well  occupied, 
the  turning  of  a  switch  sets  the  fan  in  motion  and  the  effect  is 
at  once  apparent  in  the  condition  of  the  atmosphere. 

Experience  obtained  in  testing  the  movement  of  air  by  a  fan 
has  demonstrated  that  it  is  better  and  more  economical  to  use 
a  large  fan  run  at  low  speed  than  it  is  to  move  the  same  volume 
of  air  with  a  smaller  fan  run  at  high  speed.  The  areas  of  all 
ducts  and  stacks  for  both  fresh  and  foul  air  should  be  carefully 
figured,  and  the  installation  be  made  in  such  a  manner  as  to 
avoid  all  of  the  friction  possible  in  moving  the  air.  For  this 
purpose  there  is  an  abundance  of  definite  and  dependable  data 
to  be  had. 

The  warm  fresh  air  should  enter  the  room  above  the  breath- 
ing line ;  therefore,  the  inlet  registers  should  be  located  about 
seven  and  one-half  or  eight  feet  from  the  floor. 

The  outlet  or  ventilating  registers  should  be  placed  near  the 
floor  line,  preferably  just  above  the  floor  or  the  base  board,  and 
the  location  of  both  fresh  air  and  foul  air  flues  and  registers 
should  be  in  the  inside  walls  of  all  rooms. 


FAN  BLAST  65 

Fan  Blast  Heating  with  Trunk  Line  Piping 

The  possibilities  of  good  furnace  work  are  shown  by  the  in- 
stallation of  the  hot  air  furnace  in  the  residence  illustrated  here- 
with, which  also  affords  a  good  example  of  the  fan  blast  system 
used  in  connection  with  trunk  line  piping. 

This  residence  is  a  brick  structure  containing  nine  rooms  with 
bath  and  the  usual  halls,  closets,  etc.,  and  as  the  photograph, 
Fig.  44  shows,  the  building  stands  alone  and  is  exposed  on  all 
four  sides  to  the  elements.  The  building  is  not  ventilated — that 
is,  there  is  no  provision  made  for  exhausting  the  foul  air  through 


Fig.  44^Residence  in  Which  the  Heating  System  was  Installed. 


ventilating  ducts  or  otherwise  except  by  means  of  the  fireplace  in 
the  library.  The  heating  apparatus  is  installed  in  quite  the  same 
manner  as  has  been  described  on  pages  57  to  60. 

The  fan  forces  the  cold  air  under  a  slight  and  constant  pressure 
through  the  furnace,  and  thence  into  the  various  rooms  to  be 
warmed,  thus  giving  positive  service  to  each  room.  The  em- 
ployment of  extra  large  ducts  admits  of  a  larger  volume  of  air 
supply  than  would  be  possible  with  the  regular  style  and  size  of 
basement  piping.  The  schedule  of  sizes  and  exposures  of  the 
various  rooms  is  as  follows: 


66  FAN  BLAST 

FIRST  FLOOR. 

Wall  Glass 

Wide,      Long,      High,  Surface,  Surface, 

Room.                              ft.            ft.            ft.  Cu.  ft.  Sq.  ft.  Sq.  ft. 

Living  Room   14            16            10  2,240  300  51 

Dining  Room  14            16            10  2,240  300  90 

Library    12            14.6         10  1,740  270  51 

Kitchen  14           14.6         10  2,030  220  60 

SECOND  FLOOR. 

Hall— inc.  2nd  floor 8           22           10  3,344  80  54 

Bed  Room  No.   i 13.6         15.6           9  1,881  261  42 

Sewing  Room 8.6         10             9  765  72  24 

Bed  Room  No.  2 13            14.6           9  1,692  247  42 

Bed  Room  No.  3 13            14.6           9  1,692  216  42 

Bath  Room   5.6          II              9  540  50  15 

Bed  Room  No.  4 10           14             9  1,260  216  54 


Totals 19,424         2,232          525 

The  size  of  furnace  required  may  be  determined  by  the  rule 
that  one  square  foot  of  grate  should  be  provided  for  each  5,000 
cu.  ft.  of  space  to  be  warmed. 

The  cubical  contents  of  the  various  rooms  as  shown  by  schedule 
is  nearly  20,000  cu.  ft. ;  therefore,  20,000  -=-  5,000  =  4 ;  this 
number  indicates  that  a  furnace  having  4  sq.  ft.  of  grate  should 
be  selected. 

Another  rule,  and  one  we  consider  more  accurate,  is  that  I  sq. 
ft.  of  grate  in  a  furnace  of  good  construction  is  capable  of  tak- 
ing care  of  300  sq,  ft.  of  glass  or  its  equivalent  in  exposed  wall 
surface,  4  sq.  ft.  of  exposed  wall  being  considered  equal  to  I 
sq.  ft.  of  glass. 

Having  a  total  exposed  wall  surface  (gross)  of  2,232  sq.  ft., 
and  a  total  glass  surface  (outside  doors  considered  as  glass), 
of  525  sq.  ft.,  we  proceed  as  follows :  2,232  -=-  4  =  558  equivalent 
glass  surface;  558  +  525=1,083-^300  =  3.6  sq,  ft.  requiring 
a  furnace  having  a  grate  3.6  sq.  ft.  in  area  or  about  26  inches 
in  diameter.  However,  as  we  desire  to  handle  a  larger  volume 
of  air  than  would  be  required  with  the  regular  or  old  style 
system,  we  deem  it  advisable  to  increase  the  grate  area  practically 
20  per  cent.,  and  therefore  estimate  to  use  a  furnace  having  a 
grate  area  of  4.3  sq.  ft.  or  a  grate  28  inches  in  diameter. 

Figs.  45  and  46  show  the  first  and  second  floor  plans  of  the 
residence  on  which  the  sizes  of  all  registers  and  risers  are  noted, 
and  their  location  shown.  The  compactness  of  the  system  may 
be  determined  at  a  glance. 

The  sizes  of  both  risers  and  registers  are  larger  than  would 
regularly  be  employed. 


FAN  BLAST 


67 


The  basement  plan  of  the  building  is  illustrated  by  Fig.  47,  and 
it  will  be  seen  that  the  piping  takes  up  but  little  space,  and  being 
rectangular  in  form  interferes  but  little  with  head  room  in  the 
basement. 

The  duct  work  is  constructed  entirely  of  galvanized  iron.  The 
risers  and  register  boxes  are  made  of  tin.  Each  branch  duct 
has  its  independent  damper  for  regulating  the  air  supply  to  each 
room,  and  the  casement  opening  through  which  the  cold  air  is 


Fig.  45 — Plan  of  First  Floor. 


admitted  to  the  cold  air  chamber  is  covered  with  a  window,  the 
sash  of  which  is  hinged  at  the  top  and  which,  used  as  a  damper, 
may  be  opened  or  closed  to  regulate  the  amount  of  air  delivered 
to  the  fan.  These  dampers  are  not  shown  on  the  plan. 

The  value  of  the  positiveness  of  such  a  system  as  that  illustrated 
can  scarcely  be  realized.  It  must  be  admitted  by  practical  fur- 
nace men  that  a  building  can  seldom  be  found  where  the  air  is 
properly  and,  we  might  say,  satisfactorily  supplied  and  distributed 


68 


FAN,  BLAST 


Such  installations  are  the  exception  rather  than 


by  a  furnace, 
the  rule. 

We  know  that  we  challenge  argument  by  this  statement,  yet 
we  believe  every  fair  minded  practical  furnace  man  will  agree 
with  us. 

It  seems  a  pity  that  there  is  but  one  fireplace  in  the  residence 
illustrated.  Fireplaces  are  natural  ventilating  flues,  and  a  fire- 
place in  the  living  room  and  a  ventilating  flue  in  the  wall  of 


eWfeni 


Fig.  46 — Plan  of  Second  Floor. 


the  dining  room  and  possibly  the  hall  would  make  the  system  an 
ideal  one  for  both  heating  and  ventilating  in  the  winter,  or  for 
cooling  and  ventilating  in  the  summer. 

The  fan  is  a  24"  direct  connected  electrically  driven  fan,  which, 
when  used,  is  run  at  low  speed,  is  noiseless,  and  requires  very 
little  power  to  operate  it.  The  wiring  is  connected  to  a  switch 
located  in  the  dining  room,  from  which  point  the  fan  is  put  in 
operation  or  stopped. 

A  chain  from  the  window  in  the  cold  air  box  also  runs  to  the 


FAN  BLAST 


69 


dining  room,  and  the  window  used  as  a  damper  may  be  opened 
wholly  or  in  part  without  entering  the  basement. 

By  enlarging  the  cold  air  box  sufficiently,  filters  for  removing 
dust  or  impurities  from  the  air  might  be  installed,  and  if  desired 
an  air  moistening  apparatus  might  also  be  employed. 

A  marked  improvement  in  the  system  illustrated  would  be  the 
addition  of  two  large  registers — one  in  the  side  panel  of  the 
staircase  and  one  in  the  inner  wall  of  the  living  room,  connecting 


y      i 

Fig.  47 — Plan  of  Basement. 

by  means  of  a  duct  directly  with  the  air  pit  of  the  furnace  on 
the  side  opposite  to  that  where  the  fresh  air  is  admitted. 

These  would  be  called  rotating  air  registers,  and  would  be 
used  for  rotating  or  recirculating  the  air  within  the  building  at 
periods  when  it  was  not  sufficiently  occupied  to  require  the  fresh 
air  service. 

Of  course  this  duct  would  be  properly  dampered  with  a  close 
fitting  damper  to  be  closed  when  the  fan  is  in  operation  or  when 
the  fresh  air  service  is  in  use. 


CHAPTER  VI 
ESTIMATING  FURNACE  WORK 


In  estimating  a  job  of  furnace  heating,  having  determined  the 
sizes  of  furnace,  registers  and  piping,  we  advise  the  grouping 
of  items  figured  for  the  work.  For  instance,  under  the  head 
of  "Furnace"  we  would  include  the  following: 

Cost  of  furnace,  plus  10  per  cent.,  and  freight  and  cartage. 
Foundation,  casing,  cold  air  duct,  cement  and  asbestos. 

Under  the  item  of  "Piping"  include  the  number  of  feet  of 
each  size  of  leader  or  basement  pipe,  the  number  of  feet  of  each 
size  of  riser;  then,  in  turn,  collars,  dampers,  elbows,  boots,  reg- 
ister boxes  and  any  extra  fittings. 

Under  "Ventilation"  include  the  number  of  feet  and  size  of 
circulating  pipes,  floor  register  boxes  and  any  special  dampers. 

Under  "Registers"  include  the  number  and  size  of  all  warm 
air  registers,  faces  and  borders,  the  number  and  size  of  all  ven- 
tilating registers,  faces  and  borders. 

Under  the  item  of  "Labor"  should  be  estimated  the  actual 
labor  of  installing  the  apparatus,  masonary  and  carpenter  work 
(if  needed)  and  labor  expenses,  such  as  car  fares,  board,  etc. 
In  estimating  the  labor  on  an  ordinary  house  or  residence  job 
of  furnace  heating,  it  is  well  to  regard  the  digging  of  the  cold 
air  pit  and  the  building  of  the  brick  foundation  as  constituting 
half  a  day's  labor;  and  later,  that  the  setting  of  the  furnace, 
cementing,  casing,  smoke  connection,  cutting  for  the  clean-out 
doors  and  leaders  constitute  another  half  a  day,  making  a  total 
of  one  day,  not  usually  figured.  Estimate  from  one-half  day 
to  one  day  for  cutting  holes  in  floors  and  walls,  one-half  day 
for  running  risers  and  one  day  for  ventilating  work,  setting 
registers  and  finishing.  This  totals  three  days'  work  for  two 
men,  which  should  be  sufficient  to  install  the  job  complete. 

Under  "Miscellaneous"  estimate  smoke  connection  and  damper 
and  all  incidental  expenses  not  otherwise  charged,  and  finally  add 
the  item  of  "Profit,"  remembering  that  it  costs  10  per  cent,  to  do 


ESTIMATING  71 

business,  and  if  you  add  but  10  per  cent,  to  your  figures  you  will 
lose  money  on  the  job,  besides  assuming  the  responsibility  of 
the  work.  You  are  entitled  to  a  profit  upon  your  labor  and  also 
upon  the  expenses  paid  in  shouldering  the  responsibility  of  the 
contract. 

Do  we  hear  somebody  ask  why  10  per  cent,  is  added  to  cost 
of  furnace  under  this  item?  If  so,  we  would  answer  that  it  is 
to  cover  time  spent  in  estimating  and  closing  the  job,  and  this 
rate  of  percentage  is  but  a  small  margin  to  pay  for  this  work. 


Fig.  48 — View  of  House  Used  as  Basis  of  Estimate. 

We  advise  the  use  of  a  small  loose-leaf  estimating  book,  say, 
5x7  inches  in  size,  indexed,  in  which  may  be  marked  or  pasted 
such  tables  and  data  as  will  facilitate  quick  figuring,  lists  of 
material  with  net  costs  figured  out,  etc.  Mistakes  in  estimating 
are  due  usually  to  haste  when  compelled  to  compile  an  estimate 
hurriedly,  and  a  book  with  prices,  etc.,  figured  out  at  leisure, 
the  figures  checked  to  insure  accuracy,  will  prove  invaluable  to 
the  furnace  man. 

There  are  many  rules  for  rapid  estimating,  some  of  which 
are  excellent  when  used  with  good  judgment.  Those  which 


72  ESTIMATING 

one  man  may  study  out  and  apply  with  ease  may  prove  hard 
to  adapt  by  another  man,  and  we  had  rather  employ  our  own 
data,  collected  and  classified  in  an  estimating  book,  than  to  at- 
tempt to  use  or  apply  many  of  the  rules  given  by  various 
authorities. 

The  photograph  shown  herewith  is  that  of  what  would  be 
termed  an  eleven-room  house.  It  is  of  frame  construction  and 
well  built,  the  outside  wall  being  protected  by  the  use  of  heavy 
building  paper,  applied  over  well  covered  siding,  after  which  the 


LIBRARY 
L/  i2"xi8'Side  Wall  Keg 
^  4"}/2 'Riser 
To  N.t.  Chamber 


Fig.  49 — Plan  of  First  Floor. 


walls  are  covered  with  clapboards  and  shingles.  The  building  has 
slightly  more  than  the  ordinary  amount  of  glass  exposure  and, 
as  it  stands  alone,  without  the  protection  of  adjacent  structures, 
it  may  be  considered  a  difficult  house  to  warm. 

The  building  faces  nearly  due  east,  the  chimney  noticed  on  the 
photograph  being  on  the  north  side. 

When  considering  a  furnace  job  for  a  dwelling  we  have  fre- 
quently heard  the  remark  passed  that  the  building  could  not  be 
heated  satisfactorily  with  hot  air,  owing  to  the  fact  that  it  was 


ESTIMATING 


73 


unprotected  from  the  influence  of  wintry  winds — a  statement, 
however,  which  cannot  be  borne  out  by  results,  provided  the 
heater  and  piping  can  be  properly  installed.  In  the  case  where 
such  a  statement  proves  true,  it  may  usually  be  traced  to  the  fact 
that  the  building  is  poorly  constructed  and  the  apparatus  inade- 
quate, owing  to  incorrect  estimating  or  to  the  apparatus  being 
improperly  installed. 

Fig.  49  is  a  plan  of  the  first  floor,  containing  five  principal 
rooms,  parlor,  library,  dining  room,  kitchen  and  reception  hall, 


Fig.  50 — Plan  of  Second  Floor. 


together  with  a  vestibule,  pantry  and  a  cookery  in  which  the 
range  is  located. 

Fig.  50  shows  the  second  floor,  with  four  bedrooms,  a  sewing 
room  and  bath  room. 

The  necessary  information  as  to  sizes  and  exposures  of  rooms 
should  be  tabulated  in  an  estimate  book  kept  for  the  purpose, 
and  for  this  building  the  data  would  appear  as  follows : 


74  ESTIMATING 

TABLE  OF  EXPOSURE. 

Cubic  Exposed 

First  Floor.                                     Size.  Contents.  Glass.  Wall. 

Parlor    15x15x10  2,250  72  228 

Library    15x15x10  2,250  72  198 

Dining  Room 16x16x10  2,560  64  256 

Kitchen 12  x  15  x  10  1,800  64  loo 

Reception  Hall   9  x  22  x  10  

Second  Floor  Hall  9  x  21  x  10  3,870  8l 

Second  Floor. 

S.  E.  Chamber 14  x  15  x   9  1,890  72  189 

N.  E.  Chamber 14  x  12  x   9  1,512  72  162 

Sewing  Room  7  x  g'g"  x   9  621  18  45 

N.  W.  Chamber ioxi5x   9  1,350  36  189 

S.  W.  Chamber I3xi5x   9  1,755  64  188 

Bath   Room   7x   9x   9  567 

Toilet  3'6"x   5x   9  155  46 

With  this  data  in  hand,  properly  scheduled,  the  person  es- 
timating may  use  any  one  of  the  various  rules  given  from  time  to 
time  in  these  articles  for  determining  the  size  of  furnace,  pipes, 
registers  and  fixtures.  These  we  do  not  deem  it  necessary  to 
repeat,  and  instead  will  follow  with  a  tabulated  statement  of 
sizes  of  pipes  and  registers  as  they  should  appear  on  the  record 
for  estimating. 

TABLE  OF  SIZES. 

Diameter  of    Size  of  ver-  Size  of 

Room.  cellar  pipe,      tical  flue.  register.  Notes. 

Parlor    13  in.  7  x  22  12x18      Side  wall  reg. 

Library    13  in.  7   x  22  12  x  18 

Dining  Room   12  in.     Floor  register  14  x  16      Floor 

Kitchen   12  in.  7x16  12  x  14      Side  wall  reg. 

Reception  Hall  12  in.     Floor  register  14  x  16      Floor 

S.  E.  Chamber (See  Parlor)       4"  x  12"  8"  x  12"     Wall  reg. 

N.  E.  Chamber (See  Library)     4"  x  12"  8"  x  12" 

Sewing  Room  8  in.  4"  x  10"  7"  x  10" 

N.  W.  Chamber 9  in.        3^"  x  1 1"  7"  x  12" 

S.  W.  Chamber (See  Kitchen)     4" x  12"  8" x  12" 

Bath  and  Toilet 8  in.  4"  x  10"  7"  x  10" 

Total  area  of  basement  pipes,  768  sq.  in. 

When  requested  to  furnish  an  estimate  of  the  cost  of  a  furnace 
installation,  the  heating  contractor  should  first  measure  the  build- 
ing, that  is,  obtain  the  sizes  of  the  rooms  to  be  warmed,  the 
square  feet  of  glass  surface,  and  the  square  feet  of  exposed  wall 
surface,  making  note  at  the  same  time  of  any  extraordinary 
outside  exposure. 

The  next  step  is  to  inspect  the  chimney  flue  to  which  the  fur- 
nace will  be  attached,  making  a  careful  examination  of  its  area, 
height  and  location. 

Then  observe  and  mark  the  points  of  the  compass,  the  direc- 


ESTIMATING  75 

tion  the  building  faces,  and,  as  far  as  possible,  study  the  character 
of  its  construction.  The  location  of  the  chimney  and  the  points 
of  the  compass  will  determine  where  the  furnace  must  be  set 
in  the  basement. 

Next  examine  the  basement  of  the  building  to  ascertain  if  the 
furnace  can  be  set  in  the  proper  location  to  do  the  best  work 
and  note  also,  at  the  time,  if  there  is  any  obstruction,  due  to 
building  construction,  which  would  interfere  with  the  proper 
alignment  of  the  piping.  It  is  preferable  that  the  furnace  occupies 
a  position  well  to  the  north  and  west  sides  of  the  house.  Note 
further  if  proper  provision  can  be  made  for  the  cold  air  supply, 
which  should  preferably  be  taken  from  the  north  or  west  side. 

It  is  advisable  now  to  make  a  small  sketch  of  each  floor  (not 
necessarily  drawn  to  a  scale)  and  to  locate  on  it  the  permanent 
fixtures  in  each  room,  such  as  the  tub,  closet  and  washstand  in 
the  bath  room,  the  sink,  cupboards  and  other  fixtures  in  the 
kitchen,  etc. 

The  registers  for  hot  air  heat  should  be  located  in  or  along 
the  inner  walls  of  each  room,  and  in  this  connection  note  on 
Figs.  49  and  50  the  dotted  lines  drawn  diagonally  across  the 
rooms.  The  registers  should  be  placed  at  some  point  on  the 
inner  side  of  the  room,  as  determined  by  the  dotted  lines. 

The  furnace  man  should  similarly  divide  the  rooms  on  his 
sketch,  and  then  examine  each  to  see  at  what  point  the  register 
can  be  placed  without  interfering  with  the  location  of  furniture 
and  fixtures. 

Having  obtained  the  necessary  data  and  information,  as  noted 
above,  the  contractor  may  now  return  to  his  place  of  business 
to  figure  out  his  bid  for  the  work.  The  details  of  the  job  should 
now  be  tabulated  as  given  above,  the  proper  sizes  of  all  pipes, 
registers  and  fixtures  and  of  the  furnace  being  arrived  at  by 
the  use  of  some  good  rule,  taking  into  account  the  exposure, 
glass  and  outside  wall  surfaces  of  the  various  rooms  to  be 
warmed. 

To  facilitate  the  figuring  of  costs,  the  heating  contractor  should 
have  convenient  lists,  giving  net  prices  of  registers,  register  boxes, 
various  sizes  of  leaders,  dampers,  elbows,  boots,  single  and 
double  heads,  etc.,  and  as  a  further  help,  an  estimate  blank,  pre- 
pared for  the  purpose,  should  be  used  to  show  the  various  items 
necessary  for  the  job. 

Fig.  51  shows  a  basement  plan  of  the  residence  used  for  illus- 
tration. The  location  and  size  of  furnace,  the  size  and  method 
of  running  leaders,  and  the  size  and  location  of  cold  air  chamber 
and  cold  air  duct  are  given  on  the  plan.  The  details  and  forms 
to  be  observed  and  followed  in  preparing  a  clear  and  concise 


76 


ESTIMATING 


tabulated  description  of  the  material  aand  labor  necessary  to  do 
the  work  we  shall  describe  and  discuss  herein. 

It  is  not  essential,  however,  that  the  furnace  man  adopt  the 
particular  forms  outlined  in  these  articles.  An  estimate  blank 
which  will  give,  in  order,  all  the  information  necessary  to  enable 
the  estimator  to  figure  accurately  on  the  material  required,  to- 
gether with  the  size  and  cost  thereof,  will  prove  as  valuable  and 
suitable  as  the  form  we  submit  for  this  purpose. 

A  table  showing  the  sizes  and  exposures  of  the  rooms  to  be 
warmed  is  first  necessary,  followed  by  one  giving  sizes  of  flues, 
registers  and  cellar  pipes.  With  this  information  in  hand,  next 


Fig.  51 — Plan  of  Basement. 

comes  the  selection  of  the  proper  size  of  furnace,  and  by  "proper" 
size  we  mean  that  size  that  will  furnish  the  necessary  heat  at 
a  reasonable  expense  for  fuel. 

Many  manufacturers  rate  their  furnaces  on  the  basis  of  a 
certain  number  of  cubic  feet  of  air  the  different  sizes  are  able 
to  warm,  such  as  10,000,  12,000,  15,000,  etc.  The  only  safe 
method  for  the  furnace  man  to  follow,  if  he  accepts  the  ratings 
given,  is  to  calculate  the  entire  cubical  contents  of  the  building 
to  be  warmed. 


ESTIMATING  77 

Numerous  rules  for  quick  estimating  are  practised,  a  depend- 
able one  working  on  the  basis  that  a  square  foot  of  grate  should 
take  care  of  5,000  cubic  feet  of  space.  Figuring  on  this  basis, 
we  have  in  the  residence  described  in  our  previous  article,  20,580 
cubic  feet  of  space  to  heat,  and  20,580  -r-  5,000  =  401  square  feet 
of  grate  necessary  for  the  work,  or  a  grate  27  inches  in  diameter. 

One  square  foot  of  grate  surface  is  estimated  to  be  capable 
of  caring  for  300  square  feet  of  glass  surface  or  its  equivalent, 
and  we  know  that  4  square  feet  of  wall  surface  has  about  the 
same  cooling  value  as  I  square  foot  of  glass.  Turning  to  Our 
estimate  of  sizes  and  exposures,  we  find  we  have  663  square  feet 
of  glass  and  1,555  square  feet  of  exposed  wall ;  hence :  1,555  H-  4 
=  338  +  663  =  1,051  square  feet  of  equivalent  glass;  1,051  -=- 
300  =  3.5  square  feet  of  grate,  or  a  grate  about  25^  inches  in 
diameter. 

Still  another  rule  totals  up  the  area  of  all  basement  leader 
pipes,  on  the  principle  that  the  combined  area  should  be  from 
one  and  one-fourth  to  one  and  one-half  times  the  grate  area  of 
the  furnace,  according  to  the  character  of  the  work.  Note  that 
for  the  residence  illustrated  the  area  of  the  basement  pipes  is 
768  square  inches,  and  we  estimate  a  furnace  having  a  26  inch 
grate  with  an  area  of  530  square  inches. 

Select  a  furnace  of  only  such  height  that  proper  pitch  or 
elevation  may  be  afforded  the  basement  leaders,  which  should 
pitch  upward  from  the  furnace  at  least  one  inch  in  each  foot 
of  length. 

In  estimating  the  cost  of  this  piping  it  is  customary  among 
some  furnace  men  to  figure  on  an  average  length  of  10  feet  for 
each  basement  leader — a  rule-of-thumb  method,  the  use  of  which 
should  be  discouraged — and  the  value  of  making  a  sketch  or 
plan  of  the  work  is  here  apparent.  The  basement  leaders  should 
be  erected  and  run  with  no  abrupt  turns.  Long,  circular  bends 
or  turns,  as  shown  on  Fig.  51,  should  be  arranged  for  wherever 
possible,  and,  with  a  plan  to  guide  one,  it  is  possible  to  measure 
quite  accurately  the  length  of  each  leader. 

For  each  first  floor  room  we  figure: 

Basement  leader (Size) (Length) 

Extra  for  bends (If  necessary) 

Casing  collar 

Damper  in  pipe 

Register  box  

For  the  second  or  other  upper  floors  we  figure: 

Basement  leader (Size) (Length) 

Extra  for  bends (If  necessary) 

Casing  collar 


78  ESTIMATING 

Damper  in  pipe 

Riser  (3'  longer  than  height  of  ceiling) 

Boot 

Elbow 

The  length  and  size  of  smoke  pipe  should  now  be  included, 
and  do  not  forget  to  provide  a  damper  for  the  same.  The  esti- 
mate sheet  should  show: 

Smoke  pipe — diameter,  length,  gauge  iron,  damper,  elbows. 

The  cold  air  supply  should  next  be  estimated,  and  the  follow- 
ing items  made  note  of : 

Cold  air  pit (Under  furnace) 

Cold  air  chamber 

Baffles  in  chamber (If  desired) 

Cold  air  duct 

Damper 

It  is  not  essential  that  a  printed  estimate  sheet  be  used,  but 
if  in  such  shape,  the  form  will  prevent  the  omission  of  items 
in  making  up  the  estimated  cost  of  the  work,  although  one  figur- 
ing such  work  constantly  becomes  accustomed  to  setting  down 
the  items  in  proper  rotation. 

The  cost  should  be  made  up  as  follows: 

Furnace « . .  . .   (Size)   (Kind)   

Furnace  casing 

Furnace  pit (If  necessary) 

Registers  and  borders 

(List  of  sizes,  kinds  and  costs.) 

Pipe  and  fittings 

(Here  should  follow  a  list,  room  by  room,  of  all  leaders,  bends, 

collars,  boots,  elbows,  etc.) 

Smoke  pipe  and  damper 

Cold  air  chamber 

Cold  air  duct 

Cold  air  pit 

Covering  of  piping 

Carpenter  and  mason  work 

Labor — tinner  and  helper 

Labor  expenses 

Freight  and  cartage 

Incidental  expenses   

The  above  should  form  the  basis  of  the  cost  of  the  job,  to 
which  should  be  added  the  percentage  of  profit  desired,  and  in 
connection  with  this  item  of  profit  we  would  call  particular  atten- 
tion to  a  very  common  error,  viz. : 

The  average  dealer,  having  ascertained  the  cost  of  the  work 
as  accurately  as  he  can  figure,  will,  if  he  desires  a  profit  of  20 
per  cent.,  add  this  amount  to  his  figured  cost,  and  having  secured 


ESTIMATING  79 

the  contract,  the  cost  being,  say,  $300,  for  $360,  assumes  that 
he  clears  $60  if  he  receives  $360  for  the  work,  and  possibly  rely- 
ing on  the  report  so  frequently  heard  that  it  cost  10  per  cent, 
to  do  business,  will  think  his  profit  is  $30.  Not  at  all !  Suppose 
that  the  cost  of  doing  business  is  10  per  cent,  (an  estimate  en- 
tirely too  low).  Remember  this  is  not  figuring  on  the  cost 
price,  but  rather  on  the  selling  or  contract  price.  Consider  the 
volume  of  business  done  yearly  as  $25,000,  and  the  expense  of 
doing  it  $2,500.  This  is  the  10  per  cent.  The  contract  price  is 
$360,  and  10  per  cent,  is  $36,  which  must  be  added  to  the  cost, 
making  it  actually  $300  +  $36,  or  $336. 

Now,  with  10  per  cent,  profit  added,  the  contract  price  should 
be  $336  +  10  per  cent.,  or  $369.60,  and,  as  before  stated,  this 
is  entirely  too  low,  for  the  actual  expense  of  conducting  a  busi- 
ness is  seldom  less  than  20  per  cent. 

This  charge  is  based  on  all  the  unproductive  expenses  of  the 
business,  such  as  rents,  team  and  driver,  office  help  and  all  other 
labor  not  included  directly  in  a  job,  insurance,  postage,  interest 
on  money  invested,  value  of  real  estate,  etc.,  etc.  It  is  called 
the  "overhead"  expense  of  the  business,  and,  as  such,  is  charge- 
able to  every  article  sold  or  every  contract  taken,  as  a  cost. 

Will  our  doubting  readers  figure  up  the  volume  of  their  busi- 
ness the  past  year,  total  their  unproductive  expenses  for  the 
same  period,  and  then  ascertain  their  overhead  expenses?  Do 
not  be  surprised  if  the  rate  equals  40  per  cent,  of  the  volume 
of  business  transacted,  from  which  it  must  be  appreciated  that 
this  is  doubtless  the  most  important  item  in  making  up  an 
estimate, 


CHAPTER  VII 
INTELLIGENT  APPLICATION  OF  HEATING  RULES 


The  movement  of  air  under  varying  conditions  should  be  the 
constant  study  of  the  furnace  man,  for  only  by  a  familiarity 
with  this  subject  is  he  assured  a  satisfactory  way  out  of  the 
trouble  which  sooner  or  later  will  be  met  in  the  installation  of 
his  hot  air  work.  In  the  foregoing  articles  we  have  touched 
upon  the  subjects  of  air  movement  and  air  velocities,  and  in  a 
general  manner  have  considered  the  flow  of  the  heated  air  and 
also  of  the  cold  air. 

It  is  possible  to  lay  down  certain  rules  governing  the  sizes  of 
piping,  registers,  cold  air  supply,  etc.,  but  there  never  was  and, 
moreover,  never  will  be  a  rule  to  fit  all  cases ;  therefore,  to  make 
its  use  valuable  the  rule  must  be  applied  with  good  judgment, 
and  this  good  judgment  cannot  well  be  exercised  unless  the  inter- 
ested person  is  familiar  with  and  can  adapt  it  to  the  conditions 
surrounding  the  work. 

When  estimating  on  a  job  of  furnace  heating  it  must  be  re- 
membered that  conditions  prevailing  in  a  section  where  the  ther- 
mometer scarcely  ever  reaches  zero  are  not  the  same  as  those 
prevalent  in  a  more  rigorous  climate,  say  where  a  temperature 
of  25  degrees  below  zero  is  not  unusual.  Further,  a  hot  air  heat- 
ing apparatus,  planned  and  intended  for  a  well  built  and  conse- 
quently warm  structure  would  not  suffice  for  the  same  work  if 
installed  in  a  loose,  poorly  constructed  building ;  therefore  a  rule- 
of-thumb  method  used  in  estimating  for  the  former  would  not 
give  adequate  results  for  a  building  of  the  latter  type. 

We  have  dwelt  upon  this  same  subject  from  time  to  time  in 
our  preceding  articles,  quoting  various  rules,  acting  on  the  prin- 
ciple that  information  of  such  character  cannot  be  consulted  too 
frequently  or  discussed  in  too  many  different  forms,  inasmuch 
as  it  is  the  foundation  of  all  good  furnace  heating  practice. 

The  heat  losses  of  a  building  determine  the  size  of  every  part 
of  the  heating  apparatus.  The  use  of  the  heat  unit  in  making 


APPLYING  RULES  81 

calculations  is  highly  advisable  and  can  be  followed  with  advan- 
tage. The  air  delivered  by  the  furnace  should  have  a  tempera- 
ture not  above  150  degrees,  and  140  degrees  is  better.  With  this 
temperature  at  the  furnace  the  rooms  heated  should  be  main- 
tained at  70  degrees.  The  difference,  then,  between  the  tem- 
perature of  the  furnace  and  that  of  the  rooms  is  70  degrees,  or, 
in  other  words,  in  maintaining  this  temperature  in  the  rooms 
the  air  drops  from  140  to  70  degrees,  and  in  doing  this  amount 
of  work  each  cubic  foot  of  air  delivers  i.i  heat  unit. 

Each  square  foot  of  single  thick  glass  (and  the  full  window 
opening  as  well  as  outside  doors  should  be  counted  as  glass) 
will  cool  85  heat  units  per  hour. 

Each  square  foot  of  net  outside  wall  surface  in  a  building 
of  frame  construction  (that  is,  deducting  windows  and  doors) 
will  cool  approximately  20  heat  units  per  hour. 

The  value  of  the  cooling  surface  of  brick  walls  varies  accord- 
ing to  their  thickness.  A  9  inch  wall  will  transmit  or  cool  30 
heat  units  per  hour,  a  13  inch  wall  24  heat  units. 

The  size  of  leader  or  the  area  of  the  hot  pipes  is,  of  course, 
determined  by  the  amount  of  warm  air  required,  and  this  is 
fixed  by  the  amount  lost  from  the  room  as  well  as  by  the  tem- 
perature of  the  hot  air  at  the  register. 

Working  on  the  basis  of  the  above  data,  the  loss  for  glass 
surface  will  be  85  -f-  i.i  =•  77  cubic  feet.  At  a  velocity  of  300 
feet  per  minute,  each  square  inch  of  pipe  area  will  deliver  ap- 
proximately 20  cubic  feet  of  air  per  hour ;  therefore  each  square 
foot  of  glass  will  require  77-7-  120  =  41/64,  or  about  2/3  square 
inch,  and  in  like  manner  we  find  that  each  square  foot  of  outside 
wall  surface  requires  1/7  square  inch. 

The  hourly  leakage  of  warm  air  from  the  room  will  about 
equal  its  cubical  contents,  requiring  approximately  i/ioo  square 
inch  of  pipe  area.  The  total  pipe  area  necessary  is  therefore 
2/3  of  the  glass  surface,  plus  1/7  of  the  wall  surface,  plus 
i/ioo  of  the  cubical  contents  of  the  room,  this  rule  applying  to 
first  floor  rooms.  The  flow  of  air  in  the  leader  to  a  second  or 
third  floor  room  is  probably  500  feet  per  minute,  and  proper 
allowance  should  be  made  for  the  increased  velocity,  which  will 
afford  a  reduction  of  approximately  one-fourth  in  the  area  of 
the  leader. 

For  example,  consider  a  first  floor  corner  room  12  by  15  feet 
with  a  10  foot  ceiling,  having  three  windows  3  by  6  feet  in  size. 
Glass  surface,  3  X  6  X  3  =  54  square  feet. 
Net  wall  surface,  12  -f-  15  =  27  X  10  =  270 —  54  =  216 
square  feet. 


82 


APPLYING  RULES 


Cubical  contents,  12  X  15  X  10=  1,800  cubic  feet. 

54  X      2/3  =  36 

216  X      1/7  =  3! 

i,8ooX  1/100=  18 

36  +  31  +  18  —  85  square  inches  of  pipe  area,  or  a  pipe 
about  io^4 -inches  in  diameter;  therefore  an  inch 
pipe  should  be  used. 

For  a  second  floor  room  of  similar  size  and  exposure:  85  —  21 
(one-fourth  of  85)  =  64  square  inches,  or  a  leader  pipe  9  inches 
in  diameter. 

The  total  area  of  all  leaders  should  equal  from  one  and  one- 
fourth  to  one  and  one-half  times  the  area  of  the  grate. 

The  net  register  area  should  be  25  per  cent,  greater  than  the 
area  of  the  pipe  serving  it. 


SECONDARY     OR   MOTOR     BLADP.     i 


Fig.  52 — Automatic  Air  Damper. 

Another  very  good  rule  for  determining  heat  losses  is  based 
upon  the  assumption  that  one  square  foot  of  glass  will  cool  one 
heat  unit  per  hour  for  each  degree  difference  in  inside  and  out- 
side temperature,  and  that  the  loss  through  exposed  walls  is 
one-quarter  that  for  glass  surface. 

The  rule  is :  Add  one-quarter  of  the  wall  surface  to  the  glass 
surface  and  multiply  by  75  for  rooms  having  a  south  or  south 
and  east  exposure ;  by  85  if  a  north  or  north  and  west  exposure 
for  zero  weather  temperature,  and  by  100  if  location  is  in  a  more 
rigorous  climate.  This  will  give  the  hourly  loss  in  heat  units. 

There  is  a  considerable  variance  in  regard  to  the  size  of  the 
fresh  air  duct.  Averaging  the  area  as  given  by  several  authori- 
ties demands  that  the  area  of  the  duct  for  cold  air  should  equal 
80  per  cent,  of  the  combined  area  of  all  warm  air  pipes  leading 
from  the  furnace.  We  believe  that  the  cold  air  supply  should 
equal  the  area  of  all  warm  air  leaders  in  order  to  distribute  an 
abundance  of  pure  air  to  the  rooms  heated,  and  while  fuel 


APPLYING  RULES  83 

consumption  will  be  slightly  increased  under  these  conditions, 
in  our  opinion  economy  at  or  from  this  point  should  not  be 
considered. 

In  connection  with  the  air  supply,  we  desire  to  call  attention 
to  an  automatic  atmospheric  air  damper  or  regulator  for  con- 
trolling or  restricting  the  movement  of  air  where  the  movement 
is  due  to  gravity  or  natural  conditions. 


Fig.  53 — Application  of  Damper  to  Cold  Air  Supply. 

Fig.  52  illustrates  a  small  regulator,  4  inches  high  by  12  inches 
wide,  adapted  for  a  capacity  of  80  cubic  feet  per  minute  at  a 
velocity  of  300  feet.  The  primary  or  main  blade  moves  from 
an  open  position  to  a  nearly  closed  position  and  is  actuated  by 
a  secondary  or  motor  blade.  The  motor  blade  is  located  in  a 


Fig.  54 — Fully  Open  Position. 

representative  position  to  be  acted  upon  by  the  velocity  pressure 
of  the  passing  air  and  works  against  the  action  of  the  adjust- 
able weight  shown  at  the  right  hand  side.  Both  primary  and 
secondary  blades  are  of  aluminum. 

The  opening  in  which  the  primary  blade  moves  has  circular 


84  APPLYING  RULES 

top  and  bottom,  and  the  blade  moves  back  and  forth  one-eighth 
of  a  turn,  except  on  sudden  impulses,  when  it  may  go  as  far  as 
one-quarter  of  a  turn. 

This  regulator  was  devised  by  an  engineer  at  St.  Paul,  Minn., 
and  its  application  to  the  cold  air  supply  of  a  furnace  is  shown 
by  Fig.  53. 


Fig-  55 — Partly  Closed  Position. 


At  each  of  the  two  sides  of  the  regulator  are  magnetic  retarders 
to  prevent  the  oscillation  of  the  blade  and  so  that  the  blade  moves 
from  one  position  to  another  steadily.  The  magnetic  retarding 
device  acts  as  a  retarder  with  substantially  no  resistance  and 
consists  of  an  aluminum  disc  placed  between  the  jaws  of  perma- 
nent magnets. 


Fig.  56 — Nearly  Closed  Position. 

Figs.  54,  55  and  56  show  the  device  with  the  main  blade  in  a 
fully  open,  a  partly  closed  and  a  nearly  closed  position.  When 
the  movement  of  air,  either  hot  or  cold,  is  placed  under  control 
to  the  extent  made  possible  by  this  regulator,  indirect  ventilation 
can  be  secured  with  a  greater  degree  of  positiveness  and  satisfac- 
tion than  is  possible  at  the  present  time. 


u...  I  :':::.!     I 


Fig.  57 — First  Floor  Plan. 


CHAPTER  VIII 
PRACTICAL  METHODS  OF  CONSTRUCTION 


All  methods  of  direct  heating  depend  in  operation  upon  the 
infiltration  of  outside  air  to  supply  or  replace  the  oxygen  con- 
sv.med  by  the  occupants  of  the  building  and  by  the  artificial  light- 
ing equipment.  It  is  probably  needless  to  add  that  the  amount 
so  secured  is  inadequate  to  maintain  the  air  reasonably  pure 
without,  in  addition,  opening  windows  or  doors,  and  the  relief 
afforded  by  this  latter  method,  while  partially  effective,  is  only 
obtained  at  a  direct  loss  in  fuel  consumption. 

With  the  ordinary  form  of  furnace  heating  an  abundant  quan- 
tity of  pure  air  is  supplied  when  an  outside  air  duct  is  used 
in  connection  with  the  apparatus.  It  is  obtained  without  a  re- 
circulation  of  the  air  within  the  building,  which  is  a  desirable 
condition,  for  while  recirculation  assists  the  movement  of  the 
air,  it  does  not  assist  the  ventilation.  If  the  furnace  is  of  such 
capacity  that  the  incoming  outside  supply  can  be  warmed,  when 
admitted  to  the  rooms  at  a  low  temperature,  and  at  the  same 
time  be  under  proper  conditions  of  humidity,  there  can  neither 
be  any  question  as  to  the  ability  of  such  an  apparatus  to  properly 
heat  an  average  sized  residence  or  building,  nor  any  question 
as  to  the  purity  of  the  air  it  supplies. 

We  have  known  many  furnace  men  to  advocate  the  principle 
of  taking  the  air  supply  to  the  furnace  from  all,  or  a  part,  of 
the  basement,  claiming  that  the  recirculation  of  the  air  to  the 
basement  in  this  manner  not  only  purified  it  by  reason  of  the 
natural  leakage  or  infiltration  of  outside  air  into  the  basement, 
but  also  produced  this  result  without 'the  loss  of  the  heat  units 
necessary  in  warming  cold  outside  air.  However,  we  strongly 
condemn  this  practice.  It  is  impossible  to  obtain  air  too  pure 
for  breathing,  or,  we  might  add,  too  much  of  a  supply,  and. 
according  to  our  belief,  no  better  results  can  possibly  be  secured 
than  those  obtained  from  the  use  of  a  ventilating  stack  into  which 
foul  air  ducts  from  each  room  are  connected. 


CONSTRUCTION  METHODS  87 

As  has  been  already  stated  in  these  articles,  the  air  in  a  resi- 
dence sparsely  occupied  and  lighted  with  electricity  is  but  slightly 
contaminated,  and  we  know  of  no  reason  why  such  air  should 
not  be  recirculated.  The  circumstances  surrounding  each  indi- 
vidual job  of  furnace  heating  should  determine  the  manner  in 
which  the  apparatus  should  be  installed,  and,  as  an  example,  we 
refer  to  the  residence  used  to  illustrate  this  article.  The  floor 
plans  (Figs.  57  and  58)  show  the  first  and  second  floors  of  an 
average  sized  dwelling  containing  eight  rooms,  with  the  usual 
halls,  bath  room,  and  pantry,  which  is  located  in  a  neighborhood 
free  from  dust  and  dirt,  and  the  evil  influences  of  smoke  and 
gases  emanating  from  factories  or  mercantile  establishments. 

The  level  of  the  first  floor  is  some  10  feet  higher  than  the 
street,  from  which  it  is  separated  by  a  lawn,  perhaps  100  feet 
deep,  affording  conditions  which  favor  a  pure  air  supply.  The 
fireplace  in  the  library  furnishes  an  outlet  for  the  impure  or 
contaminated  air. 

The  basement  plan  (Fig.  59)  shows  the  installation  of  the 
furnace,  cold-air  chamber  and  duct,  and  the  warm-air  leader 
pipes,  the  sizes  of  all  being  plainly  marked. 

The  cold  air  is  admitted  to  the  cold-air  chamber  through  a 
comparatively  small  opening,  the  cold-air  duct  being  nearly  twice 
the  area  ordinarily  used  in  order  that  in  zero  weather  the  harsh 
effect  prevailing  when  admitting  a  volume  of  frosty  air  to  the 
furnace  may  be  overcome.  In  mild  weather  an  abundance  of 
slightly  warmed  air  is  carried  to  the  rooms. 

The  sizes  of  risers  and  registers  are  shown  on  the  floor  plans, 
and  attention  is  called  to  the  method  of  bringing  the  warm  air 
supply  to  the  parlor  through  a  register  located  in  the  mantel,  as 
well  as  to  the  location  of  the  register,  under  window  seat  in  the 
dining  room. 

This  is  an  example  of  furnace  heating  such  as  is  in  every-day 
use  during  cold  weather,  and  the  conditions  so  ably  handled  by 
the  furnace  contractor  reflect  great  credit  on  his  judgment  and 
ability.  We  consider  the  job  worthy  of  study  and  comparison 
by  furnace  men. 

It  seems  as  if  at  the  advent  of  every  fall  season  there  is  needed 
a  series  of  articles  setting  forth  and  explaining  the  few  impor- 
tant factors  of  furnace  installation.  Whether  this  need  is  due 
to  the  fact  that  the  tinner  has  been  so  busy  with  roofing  and 
spouting  during  the  summer  months  that  he  has  forgotten  the 
many  things  learned  during  the  past  winter,  or  whether  the 
presentation  of  old  familiar  information  in  new  dress  is  required 
to  awaken  him  to  a  study  of  the  latest  ideas  in  such  installa- 
tions, we  do  not  know,  but  we  do  learn  from  observation  that 
as  soon  as  some  new  idea  or  method  is  evolved  and  offered  to 


Fig.  58 — Second  Floor  Plan. 


CONSTRUCTION  METHODS  89 

the  trade,  many  of  the  old-time  tinners  at  once  claim  Missouri 
as  their  home  and  ask  to  be  shown. 

Experience  has  demonstrated  that  a  furnace  job  in  order  to 
be  successful  in  operation  must  be  of  sufficient  size  (both  in  the 
furnace  and  accessories  used)  to  perform  the  necessary  work 
well  under  the  most  adverse  circumstances;  also,  that  it  is  im- 
portant for  it  to  be  so  constructed  that  the  air  may  travel  freely 
and  without  unnecessary  friction  from  outside  the  building 
through  the  cold-air  chamber,  cold-air  duct,  furnace,  leaders  and 
risers  to  the  registers,  if  the  building  is  to  be  heated  easily  and 
economically. 

In  order  to  arrange  for  this  result  we  must  follow  the  air 
from  its  introduction  into  the  building  to  insure  that  all  sharp 
angles  or  abrupt  turns  in  the  piping  are  eliminated  and  that 
the  connections  of  the  leaders  with  the  risers  or  stacks  are 
made  with  boots  of  such  shape  that  the  air  is  not  retarded  at 
the  base  of  the  riser.  The  old  practice  of  connecting  a  round 
pipe  leader  directly  into  a  shallow  rectangular  heat  flue  cannot 
be  too  severely  condemned. 

The  air  moves  under  a  very  slight  pressure,  a  slight  obstruc- 
tion materially  retarding  its  movement,  and  while  the  use  of 
fittings  of  special  form  will  add  considerably  to  the  cost  of  the 
job,  the  successful  furnace  man  appreciates  that  correct  practice 
calls  for  their  use  and  acts  accordingly,  often  refusing  to  install 
the  work  if  the  cheaper  competitive  methods  are  desired. 

It  is  the  desire  for  cheapness  on  the  part  of  building  con- 
tractors and  the  readiness  of  some  furnace  men  to  cater  to  this 
class  that  have  brought  furnace  heating  into  disrepute.  How 
is  it  possible  to  convince  interested  people  of  the  superior  advan- 
tages of  furnace  heating  when  the  public  mind  is  poisoned  by 
the  results  of  work  of  this  character?  The  proper  method  to 
pursue  in  order  to  raise  the  standard  is  to  absolutely  refuse  to 
install  a  job  except  given  at  a  price  which  will  warrant  the  use 
of  material,  good  in  quality  and  up  to  date  in  design. 

A  certain  large  commercial  house  adopted  as  a  slogan  the 
phrase,  "The  quality  is  remembered  long  after  the  price  is  for- 
gotten." This  motto  might  well  be  hung  with  advantage  over 
the  desk  of  the  furnace  man  to  be  kept  in  mind  when  estimat- 
ing on  and  installing  furnace  work. 

As  an  example,  consider  the  job  illustrating  this  article.  Figure 
over  the  work  from  the  data  given  as  the  job  should  be  installed, 
and  then  make  an  estimate  based  upon  cheap  competitive  work. 
The  difference  will  be  under  $100,  representing  at  prevailing 
interest  rates  $5  or  $6  a  year.  The  former  job  will  prove  en- 
tirely satisfactory  in  service,  with  a  minimum  amount  of  atten- 
tion and  fuel  consumption,  giving  a  maximum  of  comfort  and 


7 

_J 

1 

L&unc/ry 


(SegeJ-<3f>/e  Ce/fe/~ 

'x                                                              ,_, 
x       *v 
\.     X 
X      \ 

vx. 

!i 
i  • 

| 

i! 

x- 


T^ 


W'x36 


\       S\    ^    ^,  N     '    \Q"  '  * 

;:^¥/ 

/s^''. 


Co/cf  ^  /s-  Due/-        Q 


Coo/ 


Fig.  59 — Basement  Plan. 


CONSTRUCTION  METHODS  91 

convenience.  The  latter  will  prove  expensive  in  operation,  will 
require  close  attention,  and  will  consume  at  least  25  per  cent, 
more  fuel,  to  say  nothing  of  the  unsatisfactory  heat  produced. 
The  owner  will  readily  pay  the  difference  for  the  better  job, 
if  these  facts  are  properly  set  before  him.  It  is  therefore  to 
the  financial  interest  of  the  dealer  to  become  sufficiently  familiar 
with  his  subject  to  intelligently  present  these  advantages. 

School  House  Warming  and  Ventilating 

It  is  said — and  truthfully  so — that  a  man  never  stands  still 
in  his  profession.  He  either  advances,  becoming  more  and  more 
proficient,  or  loses  ground  and  finally  becomes  a  "back  number." 

There  are  many  furnace  men — good  mechanics — who,  while 
entirely  competent  to  install  almost  any  kind  of  a  warm  air  sys- 
tem once  it  is  designed  or  laid  out,  will  balk  and  appear  ignorant 
when  questioned  as  to  air  change,  the  requirements  for  ventila- 
tion, the  State  laws  governing  school  house  warming  and  ven- 
tilation, etc. 

We  illustrate  an  example  of  school  house  warming  and  ventila- 
tion designed  to  comply  with  the  requirements  of  a  State  law 
which  demands  that  each  pupil  in  each  school  room  shall  be 
supplied  with  not  less  than  30  cubic  feet  of  fresh  air  per  minute. 
This  amount  of  air  is  considered  as  a  minimum,  some  cities 
demanding  as  much  as  50  cubic  feet  per  pupil  per  minute. 

The  proper  ventilation  of  school  rooms  is  now  considered  as 
important  as  the  heating  of  them,  and  six  States — Massachu- 
setts, New  Jersey,  New  York,  Pennsylvania,  South  Dakota,  Utah 
and  Virginia — require  the  enforcement  of  a  law  demanding  30 
cubic  feet  per  minute  per  pupil. 

Main,  Montana,  North  Carolina  and  Vermont  require  the 
approval  of  school  houes  plans,  and  South  Carolina,  Minnesota 
and  Wisconsin  will  make  no  State  appropriation  to  school  dis- 
tricts who  do  not  submit  plans  which  must  be  approved  by  the 
Board  of  Education,  all  of  which  goes  to  show  that  the  various 
States  are  falling  into  line  and  adopting  the  standard  set  by 
Massachusetts,  requiring  30  cubic  feet  of  air  per  pupil  per  minute. 

Can  this  be  accomplished  when  a  furnace  is  used  for  heating? 
Yes,  but  not  with  the  furnace  alone,  as  a  purely  gravity  system 
will  not  act  with  sufficient  rapidity  to  produce  the  necessary 
change  of  air. 

By  employing  the  fan-furnace  system  for  such  service  a  defi- 
nite air  change  may  be  provided,  and  this  system  we  illustrate 
herewith. 

Each  school  room  is  heated  and  ventilated.  The  halls  and 
cloak  rooms  are  heated,  but  not  ventilated. 


CONSTRUCTION  METHODS 


bo 


CONSTRUCTION  METHODS  93 

Fig.  60  shows  a  plan  of  the  first  floor,  and  Fig.  61  a  plan  of 
the  second  floor.  Each  floor  contains  two  class  or  school  rooms, 
24  X  32  feet  in  size,  with  a  ceiling  13  feet  6  inches  in  the  clear, 
and  each  room  is  designed  to  accommodate  45  pupils. 

To  determine  the  amount  of  fresh  air  to  be  supplied  we  pro- 
ceed as  follows: 

45  X  30  (cubic  feet  per  minute)  =  1,350  cubic  feet  per 

room  per  minute. 

1,350  X  4  =  54OO  cubic   feet  per  minute   for  all   four 
school  rooms. 

To  provide  for  and  distribute  this  air  in  the  volume  required 
a  30  inch  motor-driven  disc  fan  is  installed,  as  illustrated  on  the 
basement  plan  (Fig.  62).  This  fan,  running  at  the  medium 
speed  of  450  revolutions  per  minute,  delivers  6,700  cubic  feet 
of  air  per  minute,  and  requires  about  y2  h.  p.  to  operate  it.  At 
maximum  speed,  or  575  revolutions  per  minute,  the  fan  delivers 
10,000  cubic  feet  of  air  and  requires  I  h.  p. 

This  shows  the  size  of  fan  to  be  sufficient  for  all  conditions 
of  service,  and  for  easy  and  economical  operation  a  il/2  h.  p. 
motor  is  installed. 

The  speed  of  the  fan  is  regulated  from  a  rheostat  located  in 
the  room  of  the  principal  of  the  school. 

The  warm  air  registers,  24  X  30  inches  in  size,  are  located 
about  8  feet  from  the  floor.  The  fresh  air  entering  each  school 
room  under  a  slight  pressure  is  diffused,  and,  seeking  the  cold 
walls,  is  slowly  chilled  as  it  settles  to  the  floor,  where  it  is  drawn 
off  through  24  X  24  inch  registers  into  the  ventilating  flues.  These 
registers  are  located  at  the  floor  line,  and  the  change  of  air  is 
accomplished  without  any  drafts  or  discomfort  to  the  occupants 
of  the  room. 

The  boys'  and  girls'  toilets  in  the  basement  are  ventilated  by 
means  of  special  window  ventilators. 

The  cold  fresh  air  enters  the  cold  air  room  in  the  basement 
through  two  windows  having  hinged  sash,  and  the  fan  is  placed 
in  a  32  inch  duct  leading  to  the  pit  tinder  furnaces.  A  by-pass, 
30  X  36  inches,  in  the  form  of  a  duct,  connects  the  cojd  air 
directly  from  the  cold  air  chamber  to  the  furnace  pit.  This  is 
for  use  when  the  fan  is  not  in  operation,  and  it  is  provided  with 
a  damper  which  is  closed  when  the  fan  is  in  use.  This  duct 
is  not  shown  on  the  basement  plan.  It  is  located  beneath  the 
floor,  immediately  under  the  galvanized  duct  used  in  connection 
with  the  fan. 

In  planning  the  building  the  architect  had  provided  four  flues, 
18  X  36  inches  in  area,  and  one  flue  16  X  J6  inches  in  area,  to 
serve  the  rooms  on  each  side  of  the  hall.  These  flues  are  made 


94 


CONSTRUCTION  METHODS 


bb 

£ 


CONSTRUCTION  METHODS 


95 


96  CONSTRUCTION  METHODS 

use  of  for  warm  air  and  ventilation,  as  shown  by  plans,  and 
while  they  are  somewhat  larger  than  is  necessary,  their  large- 
ness is  a  good  fault. 

The  basement  rooms  which  receive  heat  from  the  system  are 
the  play  room,  girls'  and  boys'  toilets. 

The  construction  of  the  air  pit  under  the  furnaces  is  a  partic- 
ular feature  of  the  installation.  The  furnaces  proper  are  sup- 
ported on  brick  piers,  which  are  built  in  the  pit  under  the 
center  of  each  furnace,  and  a  deflector  in  the  pit  divides  the 
cold  air  supply  uniformly  to  both  furnaces,  each  of  which  has 
a  35  inch  pot,  is  encased  in  brick  and  has  a  cast  iron  front. 

The  top  of  furnaces  is  covered  by  a  galvanized  iron  hood  or 
top  casing,  from  which  the  hot  air  trunk  lines  are  taken,  as 
indicated  on  the  plan  of  the  basement. 

The  installation  of  two  furnaces  is  desirable,  as  during  periods 
when  but  little  warmth  is  necessary  and  it  is  required  only  to 
temper  slighty  the  incoming  fresh  air,  one  furnace  will  produce 
all  of  the  heat  desired,  this  arrangement  making  a  decided  re- 
duction in  the  amount  of  fuel  consumed. 

When  estimating  work  of  this  character  and  figuring  for  a 
certain  definite  change  of  air,  there  are  some  facts  in  connec- 
tion with  the  selection  of  a  fan  which  should  be  considered. 

The  speed  of  the  fan  conditions  the  volume  of  the  air  deliv- 
ered; that  is,  the  volume  varies  directly  as  the  speed.  Doubling 
the  number  of  revolutions  of  the  fan  doubles  the  volume  of  air 
delivered. 

The  pressure  varies  as  the  square  of  the  speed;  that  is,  if 
the  speed  is  doubled,  the  pressure  is  increased  four  times  and 
the  power  required  to  drive  a  fan  varies  as  the  cube  of  the 
speed.  For  example,  if  the  speed  is  doubled,  the  power  re- 
quired is  increased  eight  times. 

It  is  therefore  more  economical  to  use  a  large  fan  at  slow 
speed  than  a  smaller  fan  at  greater  speed,  and  the  mistake  of 
selecting  too  small  a  fan  should  not  be  made.  The  motor  for 
operating  the  fan  may  be  directly  connected  to  the  fan  or  belted 
to  the  fan,  as  illustrated  on  the  basement  plan. 


CHAPTER  IX 
WHAT  CONSTITUTES  GOOD  FURNACE  WORK 


Having  so  frequently  been  asked  the  question,  "What  do  you 
mean  by  good  work?"  or  "What  constitutes  good  furnace  work?" 
we  will  proceed  to  consider  a  number  of  features  which  char- 
acterize really  good  furnace  work,  and  then  ask  ourselves  if 
we  are  conforming  to  such  a  standard. 

A  good  firm  foundation  of  masonry,  whether  of  bricks  or  of 
concrete,  is  the  first  provision  for  a  good  job.  On  new  work 
the  foundation  for  the  furnace,  and  also  the  cold  air  pit,  should 
be  built  before  the  cellar  is  cemented,  and  if  the  cold  air  is  to 
cross  a  section  of  the  basement  below  the  floor  level,  this  trench 
should  also  be  constructed  before  the  concrete  for  the  floor  is 
put  down. 

Both  pit  and  trench  should  be  constructed  of  hard  brick  laid 
in  cement,  or  of  carefully  mixed  concrete.  It  is  better  to  build 
the  walls  of  the  pit  of  brick  laid  in  cement.  The  top  of  the 
trench  may  be  built  of  concrete  laid  over  wood  forms  or  re- 
inforced with  perforated  sheet  steel  now  obtainable  for  the 
purpose. 

Dust  Discharge 

A  frequent  complaint  about  furnace  heating  is  that  dust  is 
discharged  into  the  rooms.  Ninety-nine  per  cent,  of  this  trouble 
is  caused  by  the  absence  of  a  suitable  foundation,  the  furnace 
resting  on  the  cellar  bottom,  or  upon  a  poorly  constructed 
foundation. 

The  heat  from  the  ash  pit  will  soon  dry  the  earth  bottom  so 
that  the  dust  from  it  will  be  carried  upward  into  the  rooms,  or 
if  a  poorly  constructed  or  uneven  foundation  is  used,  the  joints 
of  the  furnace  will  open  up,  due  to  the  racking  of  the  castings 
when  shaking  the  grate.  Not  only  is  this  a  source  of  annoy- 
ance, but  it  also  shortens  the  life  of  the  furnace,  and  renders 
the  castings  liable  to  cracking,  due  to  unequal  expansion  of  the 


98 


GOOD  FURNACE  WORK 


metal.    When  a  furnace  is  set  upon  an  even,  smooth  foundation 
the  parts  will  fit  in  their  proper  places  without  straining. 

The  Casing 
Having  properly  set  the  furnace,  the  next  item  of  importance 


RISER 


63 — Connection  with  Riser  Improperly  Made. 

to  consider  is  the  casing.     Some  furnace  men  prefer  a  double 
casing — the  inner  one  of  black  iron  and  the  outer  one  of  gal- 


Fig.  64— A  Connection  Better  Than  That  Shown  in  Fig.  63. 

vanized  iron  with  an  air  space  between — while  others  prefer  a 
single  casing,  covered  on  the  outside  with  asbestos  and  lined  on 


GOOD  FURNACE  WORK 


99 


the  inside  with  bright  tin,  plain  or  corrugated.  Either  method 
seems  to  us  a  mark  of  good  work.  The  practice  of  encasing 
the  castings  in  a  single  casing  is  a  mark  of  cheap  work  and 
should  be  condemned.  We  know  of  some  furnace  men  who 
use  the  single  casing  and  cover  it  with  a  black  iron  casing,  leav- 
ing an  air  space  I  to  \y2  inches  between.  This  shield  serves 
to  confine  the  heat  and  increase  the  efficiency  of  the  furnace. 

The  Furnace  Top 

The  furnace  top  has  been  discussed  in  a  former  chapter,  but 
we  would  say,  however,  that  a  top  with  a  reflector  or  cone  in 


Fig.  65— The  Best   Method  of  Making  Connection. 

the  center  which  throws  the  rising  hot  air  toward  the  outer 
circumference  of  the  casing  is  to  be  preferred  to  any  other  type. 
The  warm  air  pipes  may  be  taken  from  the  top  or  on  a  slant, 
as  the  height  of  cellar  and  character  of  the  job  will  allow.  The 
cone  fastened  to  the  under  side  of  the  top  provides  an  air  space 
in  the  center,  making  the  insulation  of  the  top  by  covering  a 
comparatively  unimportant  matter. 

The  Piping 

The  hot  air  pipes  or  basement  leaders  are  essentially  an  im- 
portant part  of  furnace  work,  and  in  laying  out  this  part  of 
the  work  the  furnace  man  should  keep  in  mind  the  fact  that 
the  installation  of  the  piping,  if  not  properly  done,  will  cause 
the  apparatus  to  prove  a  failure. 


100 


GOOD  FURNACE  WORK 


In  planning  the  piping  every  effort  should  be  made  to  elimi- 
nate friction.  This  may  be  accomplished  by  shortening  the 
runs  and  dispensing  with  all  abrupt  angles.  Every  bend  in- 
creases friction  and  reduces  the  velocity  of  the  air  current. 

Concerning  Bends 
Of  course,  bends  are  unavoidable,  but  it  is  a  mark  of  good 


Fig.   66 — Suitable   Location   for   Rotating  Register. 


work  to  find  all  bends  made  with  a  long  sweep  or  easy  turn. 
It  requires  but  little  obstruction  to  turn  a  current  of  air  which, 
owing  to  its  elasticity,  will  rebound  when  striking  a  surface 
at  a  right  angle.  Fig.  63  of  the  annexed  diagrams  illustrates 
a  connection  to  a  riser  improperly  made.  The  direction  of  the 


GOOD  FURNACE  WORK  "  101 

air  is  indicated  by  arrows.  Fig.  64  shows  a  modified  form  of 
connection,  showing  an  improvement  in  the  direction  of  air 
currents.  Fig.  65  shows  the  best  method  available,  and  the  easy 
passage  of  the  air  into  the  riser  will  be  quickly  noted.  Such 
methods  of  making  connections  indicate  good  work  and  a  knowl- 
edge of  the  handling  of  air  on  the  part  of  the  furnace  man. 

Heating  Surface 

Thus  far  we  have  said  nothing  regarding  the  value  of  large 
heating  surface — i.  e.,  a  good  generous  size  of  furnace,  particu- 
larly in  regard  to  the  fire  pot  and  grate.  A  job  may  be  ever 
so  carefully  installed,  but  if  it  be  lacking  in  capacity  it  will 
prove  inadequate  and  wasteful  of  fuel.  Good  work  demand^ 
an  economical  furnace — one  whose  grate  area  is  sufficient  to 
hold  enough  coal  to  give  off  the  necessary  heat  units  with  slov; 
combustion,  and  a  pot  and  drum,  or  heating  surface,  sufficient 
to  warm  the  volume  of  air  demanded  without  heating  to  ex- 
cessive temperatures,  and  in  this  connection  it  is  well  to  remem- 
ber that  the  higher  the  temperature  of  the  furnace  the  greater 
will  be  the  waste  of  heat  in  the  chimney. 

We  favor  the  recirculation  of  the  air  in  the  principal  room:; 
of  the  first  floor.  We  know  that  many  wise  ones  condemn 
this  practice,  yet  there  seems  to  us  no  reason  why  the  air  from 
the  living  rooms  and  hall  should  not,  under  ordinary  conditions, 
be  returned  to  the  furnace  for  reheating,  as  it  is  not  contami- 
nated to  any  perceptible  extent. 

When  rooms  in  one  part  of  the  house  are  "thrown  together," 
as  the  parlor,  reception  room,  library  and  hall,  one  large  rotat- 
ing register  placed  at  some  central  point,  preferably  in  the  hall, 
will  be  found  sufficient.  The  staircase  is  a  particularly  good 
place  for  the  installation  of  the  rotating  register,  as  the  space 
under  the  steps  allows  of  making  a  large  galvanized  duct  con- 
nection to  the  register.  Fig.  66  illustrates  the  idea. 

The  extra  expense  of  installing  the  apparatus  in  the  right 
manner  is  money  well  invested — in  fact,  like  putting  the  money 
in  a  bank  which  pays  large  dividends. 

Added  Cost  of  Hard  Firing 

If  a  heating  system  of  scant  capacity  or  of  poor  construction 
is  installed,  which  necessitates  hard  firing,  with  the  attending 
waste  of  fuel,  it  is  not  uncommon  to  find  such  an  apparatus 
using  from  20  to  30  per  cent,  more  fuel  than  would  otherwise 
be  found  necessary. 

The  additional  expense  of  installing  an  adequate  and  properly 
constructed  apparatus  would  at  this  rate  be  paid  for  in  four 


IO2  GOOD  FURNACE  WORK 

or  five  years,  and  the  annoyance  of  using  a  poor  apparatus  for 
that  period  would  have  been  eliminated.  There  is  absolutely 
no  excuse  for  doing  poor  work  or  installing  inadequate  mate- 
rial when  the  argument  of  dollars  and  cents  can  be  so  strongly 
used  with  possible  customers,  and  good  furnace  men  are  alive 
to  this  fact. 

Importance  of  Installing  High  Class  Work 

Notwithstanding  the  fact  that  the  makers  of  hot-air  heating 
apparatus,  the  heating  engineers,  physicians  and  others  in  au- 
thority, who  have  devoted  their  time  and  attention  to  studying 
the  conditions  and  results  surrounding  cheap  furnace  work, 
advocate  and  prove  the  need  of  ventilation  and  the  circulation 
of  air  in  connection  with  furnace  heating,  the  sheet  metal  worker 
or  furnace  man  unfortunately  continues  to  figure  and  install 
cheap,  unsanitary  and  unhealthful  work,  and  when  asked  the 
reason,  will  invariably  give  as  an  excuse  that  the  owner  will 
not  pay  the  additional  price  required  for  any  other  system. 
He  may  add,  further,  that  his  business  rival  will  surely  figure 
on  doing  a  cheap  job,  and  thus,  by  reason  of  the  bugaboo  of 
cheap  competition,  the  furnace  dealer  will  exert  no  effort  to  raise 
the  standard  of  furnace  work,  fearing  the  possible  loss  of  a 
contract. 

We  wish  that  it  were  within  our  power  to  impress  upon  the 
trade  the  fallacy  of  such  reasoning,  and  that  we  could  clearly 
show  to  the  contractor  the  damage  he  is  doing  to  his  business 
standing  in  the  community  and  to  his  reputation  as  a  heating 
contractor  by  installing  cheap  and  inferior  work. 

A  job  or  two  may  be  lost  by  taking  a  stand  against  and  refus- 
ing to  install  low-priced  work,  but  very  soon  a  comfortable 
business  of  the  right  sort  will  have  been  established. 

As  an  example  of  good  furnace  work,  we  show  the  basement 
and  floor  plans  of  a  compactly  built  two-and-a-half-story  sub- 
urban residence.  The  first  and  second  floors  are  of  cement  con- 
struction, and  the  third  or  half-story  is  of  frame  work. 

Fig.  67  illustrates  the  first  floor  plan,  showing  four  rooms  and 
a  pantry.  The  reception  room,  living  room  and  dining  room 
are  to  be  warmed  and  ventilated,  while  the  kitchen  is  to  be 
ventilated,  but  not  warmed. 

On  the  second  floor  (Fig.  68),  four  bedrooms  and  two  bath- 
rooms are  to  be  heated  and  ventilated,  and  on  the  third  floor, 
the  plan  of  which  is  not  shown,  a  bedroom  is  also  to  be  simi- 
larly supplied. 

The  living  room  and  dining  room  on  the  first  floor,  and  the 
bedroom,  over  dining  room,  on  the  second  floor,  are  ventilated 
by  means  of  open  fireplaces. 


GOOD  FURNACE  WORK 


103 


Fig.  67— First  Floor  Plan. 


104 


GOOD  FURNACE  WORK 


:  •»'• ; T          1  - "    ;  "•: '•'  I 1  v. '•  :•  • .' :. '  <*-&»>) w'tii&\- v.V.T  1 


Fig.  68— Second  Floor  Plan. 


GOOD  FURNACE  WORK 


105 


The  servant's  bedroom  and  bathroom  are  ventilated  by  con- 
necting the  ventilating  ducts  with  a  9  X  10  inch  ventilating  flue, 
built  against  the  kitchen  smoke  flue,  from  which  it  is  heated. 

The  ventilating  ducts  from  all  other  rooms  connect  into  a 
13  X  19  inch  vent  flue,  through  which  a  9  inch  terra  cotta  smoke 
flue  is  carried.  This  is  the  smoke  flue  which  serves  the  furnace. 
The  ventilating  flue  is  carried  up  through  the  first  story  13  X  13 
inches  in  size,  being  enlarged  before  the  ventilating  ducts  of  the 
second  floor  are  connected  into  it.  The  support  afforded  the 
tiling  in  carrying  the  weight  of  it  by  this  method  of  construction 
is  a  particularly  good  feature. 

The  kitchen  is  not  included  in  the  above  arrangement.  At  a 
point  near  the  ceiling  this  room  has  a  10  X  14  inch  ventilating 
register  connected  into  the  9  X  10  inch  vent  flue,  mentioned 
above,  for  the  purpose  of  carrying  ofl  the  steam  and  odors  of 
cooking  and  also  the  excessive  heat  from  the  range,  and  it  is 
utilized  in  both  summer  and  winter. 

The  basement  plan,  on  which  is  shown  the  furnace,  duct  work 
and  the  arrangement  for  supplying  fresh,  cold  air  is  illustrated 
by  Fig.  69. 

The  following  is  a  schedule  of  the  sizes  and  description  of  all 
pipes,  ducts  and  risers;  the  location  and  sizes  of  all  registers  are 
given  on  the  plans,  and  require  no  further  explanation : 


SCHEDULE. 


Warm  air, 

cellar    Warm  air, 
pipe,  in.      flue,  in. 


Warm  air, 
Ventilating      register,     Descrip- 


duct,  in. 


6%x  14 
6^x14 


First  Floor. 

Living  Room  1 1 

Dining  Room  1 1 

Reception    Room    and 

Halls    2—10  

Kitchen — Ventilated  at  a  point  near  ceiling  only. 


Second  Floor. 

Bedroom  No.  i 7l/> 

Bedroom  No.  2 7 

Bedroom  No.  3 pA 

Bedroom  No.  4 8 

Bath    6 

Serv.  Bath    A 

Third  Floor. 

Bedroom  No.  5 8 


size,  m. 
12  x  16 
12  x  14 


2--I2X  14 


4     xii 

3  1/2  x 

II 

10  X  IO 

3^2  x  ii 

3^2  x 

g]/2 

Sx  10 

4     x  16 

3^x 

ii 

8x  10 

4     x  i2l/2 

4     x 

ii 

10  x  10 

3/2  x   8 

3/x 

7 

7x  10 

->iX  x 

7 

10  X  10 

tion. 

Floor 

Special 

baseboard 

Floor 


Sidewall 


4     x  12^2       4     x  12^2       10x10 


The  method  of  ventilation  and  the  size  and  kind  of  ventilating 
registers  follow : 


io6 


GOOD  FURNACE  WORK 


.  69 — Basement  Plan. 


GOOD  FURNACE  WORK  107 

Ventilating 
register, 

First  Floor.  size,  in.  Description. 

Living  Room Open  fireplace 

Dining  Room 

Reception  Room  and  Halls 

Kitchen  10  x  12  Sidewall 

Second  Floor. 

Bedroom  No.   1 8  x  10 

Bedroom  No.  2 7  x  10 

Bedroom  No.  3 8xio 

Bedroom  No.  4 10  x  10  Open  fireplace 

Bath   6x   8  Sidewall 

Servants'  Bath 6x  8 

Third  Floor. 
Bedroom  No.  5 10x10 

In  building  a  ventilating  chimney  of  the  character  shown,  it 
should  be  lined  with  terra  cotta,  in  order  that  it  will  be  perfectly 
smooth  and  also  be  able  to  retain  the  heat  from  the  smoke  flue 
which  passes  through  it.  The  plan  of  the  flue  shown  on  the 
present  job  is  clearly  shown  on  the  second  floor  plan,  Fig.  68. 

The  cold  air  is  admitted  to  the  cold  air  chamber  through  a 
24  X  30  inch  screened  opening  in  basement  window,  and  baffle 
screens  for  filtering  this  supply  should  be  provided  in  the  cold 
air  chamber. 

To  obtain  the  practical  value  of  this  article,  we  ask  the  fur- 
nace man  to  make  his  own  estimate  on  this  work,  as  herein  rec- 
ommended, and  then  to  estimate  for  an  ordinary  form  of  cheap 
furnace  heating  for  the  same  house.  It  is  understood  that  the 
owner  builds  the  ventilating  chimney  and  the  ventilating  flue 
adjacent  to  the  kitchen  smoke  flue,  and  that  all  other  materials 
and  labor  are  to  be  furnished  by  the  heating  contractor. 

If  estimated  correctly  the  figures  will  show  a  difference  of 
approximately  $185,  or  a  total  difference,  when  including  the 
cost  of  the  flue,  of  about  $250. 

The  difference  in  the  results  obtained  from  increased  warmth 
and  the  comfort  and  healthfulness  of  a  perfectly  heated  and 
ventilated  home  cannot  be  measured  when  compared  with  those 
secured  from  cheap  work.  Cleanliness  and  freedom  from  dust 
are. assured  the  housewife  with  the  former,  and  finally,  as  of 
vital  interest  to  our  readers,  the  installation  of  such  an  apparatus 
is  a  standing  advertisement  to  the  furnace  man. 


CHAPTER  X 
VENTILATION 


The  sciences  of  heating  and  ventilation  are  inseparably  linked, 
and  in  the  construction  of  a  home,  both  should  be  considered 
jointly  and  proper  provision  made  for  the  installation  of  an  appa- 
ratus which  will  not  only  heat  but  ventilate  as  well.  Profes- 
sional men  and  laymen  throughout  the  country  are  awakening  to 
the  importance  of  ventilation,  and  a  word  about  it  and  its  value 
will  help  to  spread  a  proper  understanding  of  its  importance. 

By  ventilation  is  meant  the  process  of  changing  or  renewing 
the  air  within  a  room  or  building  in  order  that  the  supply  may 
remain  sufficiently  pure  for  breathing  purposes.  This  statement 
indicates  to  us  several  facts :  First,  that  ventilation  is  a  method ; 
second,  that  air  confined  within  a  room  or  building  becomes 
foul  and  unfit  for  breathing;  and,  third,  that  pure  air  is  neces- 
sary to  sustain  life. 

Ventilation  is  a  subject  which  until  recent  years  has  com- 
manded too  little  attention  from  those  who  should  be  vitally 
interested,  and  the  acquisition  of  an  adequate  system  of  ventila- 
tion in  connection  with  the  heating  system  is  not  now  the  luxury 
it  once  was  considered — it  is  a  necessity  of  today.  The  ventila- 
tion of  a  home  is  even  of  more  importance  than  the  heating  of 
it,  and  we  are  coming  to  realize  this,  making  provision  for  it  as 
we  recognize  its  worth,  and  the  time  is  approaching — and  that 
not  far  distant — when  no  dwelling  of  any  size,  or  of  the  least 
importance,  will  be  constructed  without  provision  being  made 
whereby  the  occupant  may  periodically  remove  the  foul  air  and 
admit  a  pure  supply. 

That  we  may  the  more  readily  comprehend  the  many  phases 
of  this  important  subject,  let  us  determine,  if  possible,  what  air 
is  and  note  the  properties  of  its  composition.  Air  is  an  invisible 
liquid  we  call  atmosphere,  which  surrounds  the  earth  in  a  belt 


VENTILATION  109 

several  miles  in  thickness.  It  is  invisible  (we  cannot  see  it)  ; 
it  is  transparent  (it  does  not  obstruct  our  vision)  ;  it  is  insipid 
(we  cannot  taste  it)  ;  it  is  inodorous  (pure  air  we  cannot  smell). 
It  is  composed  principally  of  oxygen  (one  part),  nitrogen 
(about  four  parts),  and  a  very  small  proportion  of  carbonic  acid 
gas  and  watery  vapor.  The  volume  of  carbonic  acid  gas  is  from 
two  to  four  parts  in  10,000.  The  amount  of  vapor  in  the  air 
is  conditioned  by  the  proximity  to  a  body  of  water  or  the  tem- 
perature of  it. 

Oxygen  is  the  life-sustaining  quality  of  the  air.  The  nitrogen 
is  necessary  to  dilute  it,  and  the  carbonic  acid  gas  to  rarify  and 
purify  it.  Carbonic  acid  gas  or  carbon-dioxide  is  poisonous,  and 
will,  when  present  in  the  air  in  any  considerable  quantity,  cause 
dullness,  headaches,  and  produce  fainting  spells.  This  condition 
is  noticeable  in  a  room  in  which  the  air  contains  10  parts  in 
10,000.  Frequently  the  air  in  a  crowded  hall  or  public  room 
is  vitiated  to  the  extent  of  25  or  more  parts  in  10,000,  rendering 
it  so  unfit  for  breathing  that  persons  having  delicate  constitutions 
will  faint.  This  is  also  true  of  many  factories  or  workrooms 
in  which  a  large  number  of  laborers  are  employed.  Air  breathed 
or  inhaled  into  the  lungs  of  people  under  conditions  such  as 
these,  inhaled  into  the  room,  and  breathed  over  and  over  again, 
is  more  or  less  laden  with,  the  germs  of  disease,  which  is  all 
the  more  deadly  should  any  of  the  persons  present  be  suffering 
from  a  malignant  affliction. 

Carbonic  acid  gas  is  the  result  of  all  combustion.  Oxygen  is 
the  life-giving  quality  in  the  atmosphere.  The  oxygen  in  the 
air  of  a  room  is  consumed  by  the  burning  of  candles,  coal  oil 
in  lamps  or  stoves,  and  by  gas.  Occupants  of  a  room  by  breath- 
ing consume  the  oxygen,  and  their  exhalations  are  full  of  car- 
bonic acid  and  other  poisonous  gases.  If  a  man  be  shut  up 
within  a  small,  tight  enclosure,  his  breathing  will  consume  the 
oxygen,  and  the  poison  and  gas  from  his  exhalations  will  soon 
act  to  poison  and  suffocate  him. 

The  amount  of  carbonic  acid  gas  in  the  air  we  breathe  should 
never  exceed  six  parts  in  10,000,  and  when  present  in  a  greater 
proportion  it  will  cause  headache  and  a  feeling  of  stuffiness. 
Relief  from  this  condition  in  the  form  of  ventilation  may  be 
had  more  cheaply  by  the  combination  of  a  ventilating  apparatus 
and  a  warm  air  furnace  than  by  any  other  method,  and  we  shall 
endeavor  to  make  this  plain  to  our  readers  as  we  progress  with 
this  discussion. 


no  VENTILATION 

It  is  well  that  we  fully  appreciate  how  vastly  improtant  is 
the  necessity  for  providing  pure  air  to  those  who  are  compelled 
to  labor  or  remain  indoors.  The  vitiation  of  the  air  is  not  caused 
entirely  by  the  respiration  from  our  bodies,  although  it  is  a  matter 
of  record  that  from  il/2  to  2l/2  pounds  of  water  are  daily  evapo- 
rated from  the  surface  of  the  skin  of  a  person  not  actively 
engaged  in  work  of  recreation — that  is,  a  person  in  still  life. 
Another  form  of  vitiation  is  the  burning  up  of  the  oxygen  in  the 
air  by  gas  lights,  coal,  coal  oil  lamps,  or  candles.  A  flame  to 
which  no  oxygen  can  reach  will  sputter  and  die  out. 

The  mechanics  of  the  sheet  metal  trade  will  understand  the 
need  of  pure  air  from  some  statistics  recently  compiled.  These 
figures  were  given  by  medical  authorities,  after  diligent  research, 
and  are  to  be  relied  upon.  Of  the  deaths  of  those  between  15 
and  45  years  of  age  in  the  United  States  last  year,  28.4  per  cent, 
died  from  tuberculosis  or  consumption.  The  death  rate  among 
certain  classes  of  labor  due  to  consumption  is: 

Marble  and  Stone  Cutters 541  of  every  100,000 

Cigar  Makers   479  of  every  100,000 

Printers    453  of  every  100,000 

Servants   430  of  every  100,000 

Formerly  the  percentage  of  death  from  consumption  among 
cigar  makers  headed  the  list,  but  the  International  Cigar  Makers' 
Union,  a  progressive  labor  body,  by  agitation  and  an  aggressive 
campaign  for  light  and  air  and  more  sanitary  workshops,  has 
reduced  the  percentage  of  deaths  from  this  disease  more  than 
50  per  cent,  in  the  last  ten  or  fifteen  years. 

This,  then,  is  the  need  of  proper  ventilation,  and  we  shall 
endeavor  to  show  how  adequate  ventilation  may  be  provided 
by  the  proper  installation  and  use  of  a  hot-air  furnace.  The 
amount  of  fresh  air  necessary  to  supply  varies  somewhat  with 
the  conditions  and  use  of  a  building,  depending,  of  course,  upon 
the  use  to  which  the  building  is  to  be  put.  Dr.  Billings,  an 
authority  on  ventilation,  estimates  as  follows: 


VENTILATION  in 

Kind  of  Building.  Cubic  Feet  Per  Hour. 

Hospitals    3,6oo  ft.  per  bed 

Assembly  Halls   3,600  ft.  per  seat 

Workshops 2,000  ft.  per  person 

Theaters 2,000  ft.  per  seat 

Office  Rooms    1,800  ft.  per  person 

The  schedule  given  applies  to  buildings  with  no  contamination 
of  the  air  except  from  the  respiration  of  the  occupants  and  the 
burning  of  the  oxygen  due  to  gas  lighting. 

Another  authority  states  that  the  amount  of  carbonic  impurity 
given  off  or  excreted  by  an  adult  female  is  0.4  to  0.5  cubic  feet 
per  hour,  and  by  an  adult  male,  0.6  to  0.7  cubic  feet  per  hour, 
the  average  for  a  mixed  assemblage  being  about  0.6. 

Dr.  De  Chaumont,  a  French  chemist,  made  some  tests  along 
this  line,  and  states  that  when  the  organic  matter  in  the  air 
begins  to  be  appreciated  (smelt)  by  the  senses,  and  the  air  is 
said  to  be  "rather  close,"  there  is  present  slightly  more  than 
four  parts  of  carbonic  impurity  per  10,000  cubic  feet  of  air. 
When  the  smell  begins  to  be  disagreeable,  and  the  air  within 
the  room  seems  "close,"  the  carbonic  impurity  is  6.5  parts  in 
10,000  cubic  feet.  When  the  smell  is  decidedly  offensive  and 
the  air  "very  close,"  the  carbonic  impurity  is  about  12  parts  in 
10,000  cubic  feet.  We  may  add  that  the  air  at  this  time  has 
reached  the  danger  point  in  its  impurity. 

Methods  of  Ventilating 

No  building  of  any  considerable  size  can  be  ventilated  except 
by  mechanical  means,  although  a  residence  or  small  building 
may  be  provided  with  a  ventilating  chimney,  which  will  answer 
every  purpose.  A  galvanized  iron  or  copper  ventilator  of  the 
type  commonly  known  as  the  "Globe,"  or  those  of  similar  con- 
struction, when  placed  on  a  one-story  building,  such  as  a  chapel, 
school  or  the  like,  will  allow  abnoxious  gases,  smoke  or  steam 
from  manufacturing  to  pass  into  the  atmosphere,  the  currents 
of  surrounding  air,  or  the  wind,  producing  a  suction  which 
exhausts  the  air  from  within  the  building.  Many  good  ven- 
tilators of  a  similar  character  are  manufactured  and  have  proven 
practical. 

A  ventilating  chimney  when  used  in  connection  with  a  hot-air 
furnace  will  give  the  very  best  results.  The  requirements  are 
that,  in  place  of  the  ordinary  brick  flue,  a  large  shaft  or  brick 


112 


VENTILATION 


shaft  should  be  erected  through  the  center  of  the  house  or  build- 
ing. Through  the  middle  of  this  stack  the  smoke  pipe  is  run, 
which,  if  the  building  be  a  low  one,  may  be  made  of  terra  cotta 
pipe,  tightly  cemented  at  the  joints.  However,  a  wrought  iron 
stack  is  preferred,  which  may  be  carried  to  any  height  desired. 
Fig.  70  shows  a  plan  of  such  a  stack,  in  which  A  is  the  wrought 
iron  stack,  and  B  the  smoke  and  ventilating  space.  Fig.  71  is  a 
sectional  view  of  such  a  stack  as  might  be  used  in  a  two-story 


Fig.  70 — Plan  of  Ventilating  Stack. 

building,  and  shows  the  stack  resting  on  a  cast  iron  bed  plate 
supported  by  a  brick  pier.  It  should  be  properly  stayed  with 
iron  braces,  one  for  each  eight  or  ten  feet  of  height.  A  good 
style  of  such  a  brace  is  illustrated  in  the  plan,  Fig.  70.  It  is 
made  of  heavy  wrought  iron  and  consists  of  a  ring  surrounding 
the  stack,  to  which  are  bolted  four  braces,  the  ends  of  which 
are  split  and  turned  in  opposite  directions  for  tying  into  the 
brickwork  as  the  stack  is  being  constructed.  On  the  top  of  the 
shaft  should  be  placed  a  heavy  galvanized  iron  hood,  supported 
by  upright  standards  of  iron  18  to  24  inches  in  length,  as  shown. 

The  wrought  iron  flue  is  placed  in  sections  and  riveted  and 
braced  as  the  stack  is  being  built.  This  is  also  true  of  the  frames 
for  the  foul-air  registers  or  openings. 

The  heat  from  the  smoke  pipe  or  flue  will  expand  the  air  in 
the  ventilating  shaft  and  cause  an  upward  movement  of  the  air, 
which  will  exhaust  the  foul  air  from  each  room  connected  to  it. 

A  cold  flue  is  of  no  use  as  a  ventilating  shaft,  inasmuch  as 
no  means  being  provided  for  expanding  the  air  and  overcoming 


VENTILATION  113 

the  pressure  of  the  atmosphere  (14.7  pounds  at  sea  level),  the 
air  in  the  flue  remains  "dead"  or  inactive,  and  it  is  absolutely 


Fig.  71 — Sectional  View  of  Ventilating  Stack. 

necessary  to  overcome  this  pressure  on  the  flue  before  an  upward 
movement  of  the  air  in  the  shaft  can  take  place. 


CHAPTER  XI 
VENTILATION  BY  THE  USE  OF  PROPELLER  FAN 


In  the  preceding  chapter  we  discussed  a  method  of  ventila- 
tion that  might  be  termed  "natural  ventilation."  However,  not 
all  buildings  are  so  constructed  that  a  ventilating  flue  of  the 
character  mentioned  therein  can  be  erected  except  at  such  a  con- 
siderable expense  that  the  owner  is  loath  to  consider  such  a  sys- 
tem. Since  electricity  has  become  so  common  for  lighting  pur- 
poses, and  by  reason  of  the  fact  that  nearly  every  town  has  a 
separate  electric  plant,  or  contracts  for  electric  current  from 
some  adjoining  city,  the  matter  of  obtaining  proper  ventilation 
of  our  homes,  or  in  other  buildings,  can  easily  be  arranged  for. 
By  this  statement  we  refer  to  the  proper  use  of  an  electric  pro- 
peller fan. 

This  covers  a  method  which  should  be  carefully  studied  by 
the  furnace  man.  It  is  one  so  simple  of  adaptation,  and  yet  so 
effective  in  operation,  that  it  provides  a  long-felt  want. 

The  electric  current  ordinarily  used  by  an  incandescent  burner 
is  sufficient  to  operate  a  fan  which  will  thoroughly  ventilate  any 
residence  of  medium  proportions  and  construction,  and  the  ex- 
pense of  running  the  fan  is  so  slight  as  to  be  scarcely  worthy  of 
mention,  particularly  when  the  results  attained  are  regarded  in 
their  true  light. 

We  have  reference  to  the  propeller  type  of  fan  as  illustrated 
in  Fig.  72.  A  fan  of  this  character  is  designed  to  move  air 
against  a  very  slight  resistance,  the  blades  being  curved,  pro- 
pelling the  air  forward  by  impact,  and  when  installed  in  the 
attic  of  a  building  it  exhausts  to  the  atmosphere  direct  or  through 
a  short  duct. 

A  system  of  ventilation  of  this  kind  consists  of  register  faces 
or  open  panels  placed  in  the  baseboard  of  each  room  to  be  ven- 
tilated and  connected  to  an  upright  tin  or  galvanized  iron  duct 
from  each  room,  terminating  in  the  attic  of  the  building,  which 
is  used  as  a  plenum  chamber.  An  opening  in  one  of  the  gable 
ends  of  the  attic  is  made  and  framed  to  the  size  and  diameter 
of  the  fan,  the  flange  of  which  is  bolted  to  this  frame.  An 


FAN  VENTILATION  115 

attic  window  may  be  arranged  for  the  purpose,  the  framework 
being  built  in  such  a  manner  that  the  window  may  be  closed 
when  fan  is  not  in  use.  See  Fig.  73. 

The  fan  is  now  ready  for  the  wiring  to  the  motor.  A  rheostat 
or  speed  controller  is  attached  in  a  convenient  place  on  the  first 
floor,  by  which  the  fan  may  be  started,  stopped  or  the  speed  of 
it  controlled.  These  fans  are  made  for  two  speeds,  namely, 
medium  and  maximum.  Medium  speed  fans  vary  according  to 
size  in  the  number  of  revolutions  per  minute,  from  800  for  the 
18  inch  to  200  for  a  fan  6  feet  in  diameter,  and  this  type  is  rec- 
ommended for  ordinary  ventilating  work  on  account  of  being 
practically  noiseless  in  operation. 

Maximum  speed  fans  vary  from  1,000  revolutions  for  the 
1 8  inch  to  270  for  a  6  foot  fan. 

The  following  table  gives  the  size,  revolutions  per  minute, 
horse  power  and  cubic  feet  of  air  moved  for  medium  speed 
fans  from  18  to  72  inches  in  diameter: 


Propeller  Fan. 


Diameter  of 
fan,  inches. 

18 
24 

32 
36 

42 
48 
60 

72 


Horse 
power. 

1/8 


1/2 

5/8 

3/4 

13/4 

2  1/2 


Revolutions 
per  minute. 

800 
600 
450 
425 
350 
300 
250 

200 


Cubic  feet  of 
air  delivered. 

2,000 

4,000 

6,700 

9,500 
12,600 
16,700 
25,700 
37,000 


In   handling  or  moving  air  by   a   fan   the   amount   delivered 


n6 


FAN  VENTILATION 


depends  upon  two  factors,  viz.,  size  and  speed.  Further,  if 
the  air  is  forced  through  a  duct  or  ducts,  the  element  of  friction, 
due  to  resistance  encountered,  must  be  considered. 

There  are  some  few  rules  which  it  will  be  well  to  remember : 
i.    The  amount  of  air  delivered  by  the  fan  varies  directly  as 
the  speed  of  it.     Doubling  the  number  of  revolutions   doubles 
the  volume  of  air  delivered. 


Fig.  73 — Propeller  Fan  in  Attic  Window. 


2.  The  air  pressure  varies  as  the  square  of  the  speed;  for 
example,  if  the  speed  is  doubled  the  pressure  is  increased  four 
times.     As  we  desire  by  the  method  described  to  deliver  the  air 
directly  to  the  atmosphere,  this  rule  need  not  be  regarded  as 
important  for  our  purpose. 

3.  The  power  required  is  increased  eight  times  when  the  speed 
is  doubled.     Thus  it  is  more  economical  to  use  a  large  fan  at  a 
low  speed  than  a  small  fan  at  a  high  speed  to  move  the  same 
volume  of  air. 

4.  The  temperature  of  the  air  to  be  moved  affects  the  pres- 
sure  required  and   the   power  necessary.      Increasing  the   tem- 
perature of  the  air  reduces  its  weight  and  diminishes  the  power 
necessary  to  handle  a  given  volume. 

Let  us  consider,  in  ventilating  an  eight-room  house,  that  there 


FAN  VENTILATION  117 

are  five  rooms  in  which  the  air  is  to  be  completely  changed  four 
times  hourly.  These  rooms  average  15  X  20  feet  and  have  10- 
foot  ceilings.  15  X  20  X  10  X  5  =  15,000  cubic  feet  of  air  to 
be  moved,  which,  when  multiplied  by  four,  the  number  of  air 
changes,  equals  60,000  cubic  feet  to  be  moved  hourly,  or  1,000 
cubic  feet  per  minute.  By  reference  to  the  table  given  above 
it  will  be  seen  that  only  a  very  small  fan  is  necessary  for  this 
work. 

The  proper  amount  of  pure  fresh  air  must  be  admitted  through 
the  cold  air  duct  and  warmed  by  the  furnace  to  such  a  degree 
that  the  various  heat  losses  of  the  rooms  are  taken  care  of  and 
a  uniform  desirable  temperature  is  maintained. 

Many  heating  contractors  contend  that,  providing  the  impure, 
contaminated  air  is  removed  by  an  exhaust  fan,  the  inward 
leakage  around  windows  and  doors  is  sufficient  to  supply  all 
of  the  pure  air  necessary  for  the  ordinary  residence.  This  is 
not  true,  for,  considering  that  this  applied  to  the  building  noted 
above,  it  would  be  necessary  for  200  cubic  feet  per  minute  to 
leak  into  each  of  the  five  rooms  figured,  and  cold  air  admitted 
in  such  quantities  would  produce  unpleasant  drafts  dangerous 
to  the  health  of  the  occupants.  One  of  the  first  considerations 
in  the  movement  of  air  for  ventilation  is  that  there  shall  be  no 
drafts  experienced  by  the  occupants  of  the  room  or  building. 

There  is  a  great  advantage  in  installing  a  fan  of  this  charac- 
ter, viz.,  that  proper  ventilation  may  be  provided  during  the 
warm  weather  period,  when  the  heating  apparatus  is  not  in  use. 
The  effectiveness  of  any  method  is  measured  by  the  conditions 
of  the  weather.  A  heavy  atmosphere  or  excessive  velocities  of 
the  wind  will  have  a  much  greater  effect  upon  any  system  of 
natural  ventilation  than  it  will  upon  a  positive  mechanical  system 
as  above  described. 

Let  all  furnace  men  become  acquainted  with  every  phase  of 
this  all  important  subject.  There  is  no  doubt  but  that  heating 
and  ventilation  are  to  be  inseparably  bound  together,  and  we 
must  look  to  our  system  of  warming  to  assist  us  in  our  methods 
of  ventilation.  On  the  other  hand,  every  furnace  man  of  experi- 
ence knows  also  that  it  is  easier  to  warm  a  well-ventilated  build- 
ing than  it  is  to  heat  one  in  which  the  air  is  foul  or  dead. 

Efficiency  of  the  Exhaust  Fan 

Exhaust  fans  are  efficient  for  clearing  factory  rooms  of  smoke, 
poisonous  gases  or  the  fumes  from  chemicals  used  in  manufac- 
turing, and  by  the  admission  of  a  sufficient  quantity  of  fresh  air 
properly  warmed  it  is  possible  to  keep  the  rooms  at  a  comfort- 
able temperature  and  the  air  fresh  and  pure.  Furnaces  may  be 
used  in  connection  with  exhaust  fans  for  this  purpose,  and  for 


n8  FAN  VENTILATION 

warming  and  ventilating  small  factories  or  other  buildings  a 
system  of  this  kind  is  efficient  and  may  be  installed  at  low  cost. 
The  fan  may  be  driven  by  a  motor,  belt  driven  or  direct  con- 
nected, and  as  nearly  all  of  the  larger  towns,  as  well  as  cities 
of  any  size,  have  an  electric  light  and  power  plant,  the  power 
to  operate  the  fan  may  be  secured  at  a  nominal  cost,  as  an 
exhaust  fan  run  at  low  speed  requires  but  a  small  amount  of 
power  to  drive  it,  owing  to  the  fact  that  the  air  is  usually  moved 
against  a  very  slight  resistance. 

In  this  connection  we  quote  from  an  article  by  Wm.  H.  Hayes 
which  was  recently  published  in  SHEET  METAL.  Mr.  Hayes  says: 

"I  am  indebted  to  one  of  the  largest  and  best  known  blower 
concerns  for  the  capacity  table  printed  in  this  article.  This  is 
presented  for  the  reason  that  the  power  required  to  drive  ex- 
hausters is  an  important  factor  when  a  deal  is  being  negotiated 
in  the  piping  business.  Yet  it  is  a  factor  very  often  regarded 
as  one  of  small  importance. 

"By  referring  to  this  table  the  reader  will  see  how  increasing 
the  speed  of  a  fan  by  a  few  revolutions  will  more  than  double 
the  amount  of  power  required  to  drive  it.  Take,  for  example, 
the  40  inch  exhauster  fourth  in  the  lower  table;  4  horse  power 
will  drive  it  1,090  revolutions  per  minute,  yet  to  drive  it  1,785 
revolutions,  an  increase  of  speed  of  but  695  revolutions,  requires 
17.35  horse  power.  The  reader  will  note  also  the  last  stat:ment 
made  underneath  the  table,  viz. :  'If  the  suction  area  is  less 
than  the  inlet  of  the  fan,  the  power  and  volume  will  be  reduced 
and  the  pressure  increased.'  Thus,  if  it  is  a  question  of  power 
with  the  prospective  purchaser,  sell  him  a  larger  fan. 


Speed,  Capacity  and  Horse  Power  Required  for  Steel  Plate 

Exhaust  Fans 

"I  am  indebted  to  the  same  concern  for  another  table,  given 
below,  and  which  shows  how  speed  can  be  cut  down  and  power 
saved  by  adopting  t'.ic  suggestion. 

"To  quote  the  American  Blower  Company:  'Supposing  we 
have  284  square  inches  of  area  in  all  the  branch  pipes  and  the 
main  suction  pipe  after  the  last  branch  is  taken  in — 19  inches 
in  diameter.  The  various  sizes  of  fans  which  can  be  applied, 
with  their  respective  results,  are  shown  in  the  table  below,  this 
being  based  on  100  feet  of  suction  pipe,  100  feet  of  discharge 
pipe,  four  elbows  in  the  pipe  and  a  properly  proportioned 
separator : 


FAN  VENTILATION  119 

Brake   voc^^RJ^rt'ONC>0x^vr5fBrake00  ^^  ^ooo^oot/jrt 
horsepow'r  o  ^  »-<  oi  oi  co  -<f  ^t  10  IN.  I  horsepow'r^o  o\  £  K  HJ  t<  oj^  o\  UJ>^H  ^  ^ 

c«  per  minute  ~  of  co  co  uSvcT  t^co  o  co'  [  per  minUvte  <^  Tf  vo"  K  o1  of  10  tx  ^"oo"  ^  <u 


P    TVT 
jr.  ivi. .  . 


oo  10  IN 


horseoow'r  "^  ^  ^  *>  ^    •  M.  ^  ^  '  horsepow'r  rj-vd  od  w  rj- 1<  ^  10  ON  d\'C  J3 

•r  OO*™*1™^*™1*^^    CO  CO  Tj"  fl\  »^    HH    KH    o^    04    O4    CO»T—J  "^    Q-^ 


°    05 

f    ^  ^ 


C^  u<  /^*    t  *          .f  2.     O  l*^  O  *O  OOQOOQt^'^rH 

1-1  Cubic       ft     ^O^OOOiOioOOn.  V^UDIC       I  t  .  0\  t^vo  00'^<^'QO*OO^*« 

^  per  minute  ^  ?"?  "t  °7  ^  ^  ^  ^  °    .  per  minute^-^  SS^oJ  d  S  Sc5  ^f  a  ^  *S 


O   M  NO   W  Q\  W  tX  O\  O\-N    I    TJ      p     TIT         04   CO  »O  TfOO   ^fcoO4   Ol   O'>"£    ^i 

ID    r>    TVT       o  *-"  tx  t^oo  oi\oo>oo   1-tV'  *  •  •"*••  »-<i-orxiocooi  M  o  o»oo  >      '^ 
JX.   lr^.  JVl.       01  o  oo  t^»vc  voioiori-Tf  (a^^^^t^^^  bf . . 

cr       tn 

Brake    O  ^  Os  ^  «x  o  to  co  ^  vo  f  ?  r  a  k  ^  ^.^ 
i   d  «.  C>corj-iot>q\o4  ^-^qtv.1  horsepow  r  oi  co 
,  horsepow  roooooMM^oioiiu 

tn 


R   P   M 

• 


Diam.  inlet  f  B  r  a  k  e  ,v 


,vo  jovo  o  vo  tooo  o 
(inside)in.2  a  ^^  o^  ol  ot  ^  oT       orsepow'r  2  3  ^  ^  S£  K  S  d  5 


0 


p  e  riphery.«>-«>^: 
N  inches  °"  2  rj  J?  2"  ^"2  N-  per  minute  -  w  ^  ^^T  K  a  ^  oi  t<^ 

O  O  e 


.  P.  M... 

OH  « 

to 

^ 
No.  of  fanffg^SRSSRig     No.  of  fan^ft^^^^^  R<2         .2 


I2O  FAN  VENTILATION 


Size  of  fan.  Speed.  Horse  power. 

45  inches  1,300  R.  P.  M.  n  2/3 

50  inches  1,010  R.  P.  M.  8  3/4 

55  inches  810  R.  P.  M.  7  " 

60  inches  650. R.  P.  M.  5  2/3 

"Thus  it  will  be  seen  that  to  use  a  60  inch  fan  instead  of  a 

45  inch  fan  is  to  reduce  the  power  more  than  one-half." 


CHAPTER  XII 
HUMIDITY  AND  THE  VALUE  OF  AIR  MOISTENING 


Up  to  the  present  time  practically  every  furnace  man  seems 
to  have  had  but  one  object  in  view  when  installing  a  hot-air 
furnace;  namely,  to  install  a  furnace  of  such  size  and  in  such 
a  manner  that  each  dwelling  or  building  may  be  satisfactorily 
warmed,  notwithstanding  the  most  adverse  conditions  of  wind 
and  weather  prevailing.  True,  there  are  those  in  the  trade  who 
keep  in  touch  with  all  the  later  improvements,  who  read  and 
study  the  results  of  various  experiments  calculated  to  better  the 
general  conditions  of  warm-air  heating — in  other  words,  k^eps 
up  to  date — but  they  are  few  in  number. 

Humidity  and  the  value  of  air  moistening  cover  a  subject 
that  should  be  carefully  investigated  and  learned  by  all  heating 
contractors.  It  is  a  subject  easy  to  understand  and,  when  prop- 
erly understood,  easy  of  application.  Many  articles  of  great 
value  on  this  topic  appear  from  time  to  time  in  the  trade  press, 
and  the  furnace  man  who  gives  them  but  scant  or  passing  atten- 
tion is  missing  instructive  literature  which  will  later  prove  of 
vast  importance  and  necessity  to  him. 

We  know  that  the  earth  is  surrounded  by  a  belt  of  atmos- 
phere several  miles  in  thickness  and  that  this  air  contains  more 
or  less  vapor,  the  amount  varying  according  to  the  temperature 
or  its  proximity  to  a  body  of  water.  Those  of  our  readers  who 
have  lived  in  the  vicinity  of,  or  have  visited  the  shore  of  any 
one  of  the  Great  Lakes,  or  even  many  of  those  inland  bodies 
of  water  less  extensive  in  area,  may  have  noticed  that,  as  a 
rule,  they  lie  in  a  basin  and  are  approached  down  a  hill,  which 
is  sometimes  very  short  and  abrupt,  and  again  at  other  times 
long  or  gradual  in  its  descent.  No  matter  which  geographical 
condition  exists,  it  is  very  apparent  that  the  atmosphere  after 
the  crest  of  the  hill  is  passed  becomes  very  balmy,  humid  and 
of  a  satisfying  nature,  all  of  which  is  due  to  the  proximity  of 
the  body  of  water.  We  may  reach  or  obtain  this  same  delight- 
ful condition  and  enjoy  this  same  balmy  atmosphere  within  our 
homes. 

The  writer  believes  that  this  subject  is  too  little  understood 
and  is  given  too  little  attention  by  furnace  men. 


122  AIR  MOISTENING 

The  great  Architect  of  the  Universe  never  intended  that  we 
should  pass  one-third  or  more  of  our  lives  shut  up  in  almost  air 
tight  boxes ;  neither  did  he  intend  that  we  should  be  compelled  to 
breathe  tainted  and  poisoned  air,  yet  this  is  what  we  are  doing 
day  after  day  with  the  result  that  as  a  nation  we  are  heir  to  all 
sorts  of  diseases  of  the  throat  and  lungs,  tuberculosis,  bronchitis, 
etc. 

This  condition  and  the  effects  of  it  will  perhaps  be  better 
realized  when  we  say  that  statistics  show  that  over  30  per  cent, 
of  all  deaths  in  this  country  are  due  to  diseases  of  the  throat  and 
lungs,  and  today  the  treatment  most  generally  prescribed  by  the 
physicians  for  such  ailments  is  more  fresh  air,  and  by  this  advice 
is  not  meant  the  outside  air,  such  as  comes  to  us  within  our  homes, 
baked  by  the  average  heating  apparatus,  but  clean,  pure,  and 
humid  air,  such  as  an  out-of-door  climate  provides. 

There  is  no  form  of  artificial  warming  apparatus  by  which  this 
ideal  condition  may  be  produced  and  sustained  so  well  as  by  a 
hot  air  warming  system  properly  installed. 

The  average  steam  or  hot  water  warming  apparatus  provides 
only  for  heat.  The  introduction  of  a  supply  of  fresh  air  is 
generally  overlooked  entirely,  or  when  introduced  at  all  is  only 
provided  for  in  the  homes  of  well-to-do  people,  who  have  ample 
means  to  pay  the  increased  expense  of  installation  and  main- 
tenance of  such  an  apparatus. 

As  we  have  said  before,  it  is  by  reason  of  the  moisture  in  the 
air  that  it  carries  and  retains  heat,  and  the  dryer  the  air,  the 
more  difficult  it  is  to  heat. 

The  air  is  capable  of  carrying  a  large  amount  of  moisture. 
This  may  be  noticed  during  a  fog  and  again  by  the  dew  deposited 
during  the  night  at  certain  seasons  of  the  year.  In  tropical  coun- 
tries the  dew  deposited  is  frequently  so  heavy  that  the  eaves  drip 
water,  and  if  this  condition  did  not  exist  the  tropics  would  not 
be  habitable. 

A  year  or  two  ago,  when  discussing  the  importance  of  air- 
moistening,  the  writer  remarked  somewhat  as  follows:  "The 
process  of  refining  or  manufacturing  raw  material  into  a  finished 
product  has  been  carried  on  for  many  centuries.  Had  some- 
body stated  to  the  architects  of  ancient  Rome,  or  to  the  archi- 
tects and  constructors  of  our  own  national  capitol,  or  of  our 
more  modern  buildings,  that  in  the  twentieth  century  we  would 
be  manufacturing  climate,  they  would  all  alike  have  disbelieved 
the  statement,  and  considered  that  the  speaker  was  bereft  of 
reason."  However,  that  is  exactly  what  we  are  accomplishing1 


AIR  MOISTENING  123 

in  hundreds  of  buildings  today  and  it  has  come  to  be  a  very 
important  factor  of  an  up-to-date  heating  and  ventilating  ap- 
paratus, more  particularly  in  our  schools  and  public  buildings. 
We  can  now  provide  an  air  supply  for  any  building  that  will  be 
free  from  soot  and  dust,  that  will  be  pure  and  also  accompanied 
by  a  constant  relative  humidity,  regardless  of  the  condition  of 
the  outside  air,  or  the  location  of  the  structure. 

The  principal  installations  of  air-moistening  apparatus  have 
been  placed  in  connection  with  the  fan  or  blower  system  of  heat- 
ing. Very  few  have  as  yet  been  used  with  a  warm-air  furnace 
as  the  source  of  heat. 

Let  us  consider  briefly  the  term  humidity  with  the  fact  that  it 
is  necessary  that  there  be  some  moisture  in  the  air  we  breathe. 
When  the  air  is  so  laden  with  moisture  that  it  is  deposited  in  the 
form  of  de\v,  it  has  reached  the  point  of  complete  saturation, 
or  what  is  k.iown  as  the  "dew  point."  This  deposit  or  dew  is 
formed  by  the  radiation  or  giving  off  of  heat  from  trees,  plants, 
etc.,  this  action  reducing  the  temperature  of  the  surrounding 
air  to  the  point  of  complete  saturation,  when  the  moisture  will 
be  deposited.  We  will  consider  that  this  point  is  one  hundred 
per  cent.  In  the  most  arid  deserts  there  is  some  degree  of 
moisture  present  in  the  air,  probably  thirty  or  thirty-five  per 
cent,  of  complete  saturation.  In  ordinary  or  temperate  climates 
the  prevailing  percentage  may  be  from  fifty  to  seventy-five,  the 
rate  depending  largely  upon  the  temperature. 

The  dryer  the  air,  the  more  difficult  it  is  to  heat.  At  high 
altitudes  the  atmosphere  is  dryer  than  that  found  at  low  points, 
hence  it  is  cooler  and  more  difficult  to  heat,  as  the  cold  air  ab- 
sorbs less  moisture  than  the  warm.  On  a  hot  summer's  day, 
with  the  thermometer  around  90  degrees  Fahr.,  the  air  is  capable 
of  absorbing  about  fifteen  grains  of  moisture  for  each  cubic 
foot.  At  32  degrees  Fahr.  (freezing),  the  air  will  absorb  but 
little  more  than  two  grains  per  cubic  foot.  It  is  apparent  then 
that  by  reason  of  the  moisture  present,  the  air  carries  and  re- 
tains heat.  The  heating  apparatus  which  employs  an  air-mois- 
tener  to  properly  saturate  or  humidify  the  air  is  not  only  provid- 
ing a  healthful  climate  within  the  building,  but  is  accomplishing 
it  at  less  cost  for  maintenance  than  would  otherwise  be  possible. 


Reduction  of  Fuel 

Exhaustive  tests  have  demonstrated  the  fact  that  the  saving 
in  fuel  effected  by  adopting  proper  methods  of  air  moistening 
will  pay  the  cost  of  such  effort  to  say  nothing  of  the  increased 
comfort  and  health  fulness  secured  and  probable  saving  in  the 
expense  of  physicians'  services. 


124  AIR  MOISTENING 

Results  of  Investigation 

One  physician  says:  "Investigations  have  proven  that  the 
higher  the  degree  of  temperature,  which  increases  the  capacity 
for  water,  the  greater  will  be  the  weight  of  a  cubic  foot  of 
saturated  aqueous  vapor;  therefore,  by  the  addition  of  heat  to 
the  colder  outside  atmosphere  entering  the  building,  there  must 
be  an  additional  amount  of  vapor  added  to  overcome  the  de- 
ficiency existing  between  the  weight  of  a  cubic  foot  of  saturated 
aqueous  vapor  as  received  from  the  furnace  from  the  outside, 
and  the  weight  of  a  cubic  foot  of  saturated  aqueous  vapor  raised, 
by  the  addition  of  heat  units,  to  the  higher  indoor  temperature 
to  produce  a  normal  condition  of  the  latter/' 

So  much  regarding  the  need  of  proper  humidity.  Now,  let 
us  for  a  moment  consider  the  effect  of  it  in  connection  with  the 
proper  warming  of  a  house  or  other  building. 

We  have  said,  and  our  readers  have  no  doubt  frequently  read 
the  statement,  that  a  room  heated  to  60  degrees  F.,  with  a 
humidity  of  55  per  cent.,  is  much  more  comfortable  than  a  room 
heated  to  75  degrees  with  a  lower  percentage  of  humidity.  The 
climate,  and  when  warmed  to  60  degrees  F.  a  building  is  com- 
fortably heated.  In  this  country  we  all  know  that  a  tempera- 
ture of  70  degrees  F.  is  the  standard  for  living  rooms,  offices, 
or  other  rooms  where  the  occupants  are  inactive. 

The  average  warmed  building,  having  no  ventilation,  is  as  dry 
as  the  desert  of  Sahara,  and  many  eminent  physicians  have  called 
attention  to  the  bad  results  arising  from  it.  The  irritation  of 
the  mucous  membrane  of  the  throat  and  lungs,  causing  bron- 
chitis and  catarrh,  is  one  of  the  worst  evils  consequent  upon  this 
condition  of  the  air. 

If  in  cold  weather  we  are  using  outside  air  to  supply  the  fur- 
nace, and  this  outside  air  is  at  65  per  cent,  (as  we  measure 
humidity),  we  reduce  the  moisture  to  probably  30  or  35  per  cent, 
in  warming  our  rooms  to  70  degrees  Fahr.  In  continuing  to 
pour  warm  air  into  the  rooms  under  these  conditions  the  radiated 
heat  seems  to  penetrate  through  the  air  within,  but  without 
warming  it.  If  we  devise  and  employ  some  method  of  moisten- 
ing it,  the  moist,  humid  air  will  hold  and  absorb  the  radiated 
heat  and  give  it  off  to  all  cooler  bodies  within  the  room. 

Humidity  has  been  aptly  called  "Nature's  great  bed-blanket 
for  all  her  children,"  and  without  it  they  would  perish.  Dry  air 
extracts  the  moisture  from  the  body,  and  it  is  accordingly  neces- 
sary to  warm  the  rooms  to  a  greater  degree  in  order  to  feel  com- 
fortable. 

If  our  readers  will  note  the  difference  between  the  English 
climate  and  that  of  America,  a  very  good  illustration  of  these 


AIR  MOISTENING 


125 


facts  is  apparent.  The  Englishman  complains  of  the  American 
winter  climate  because  our  homes,  which  to  us  are  only  comfort- 
ably warmed,  are  to  him  overheated.  The  American  finds  the 
reverse  to  be  the  case  when  visiting  England,  and  complains  of 
the  cold.  The  human  body  can  be  likened  to  a  furnace  and  the 
heat  developed  within  it  must  be  given  off  as  rapidly  as  it  is 
produced  if  we  are  to  remain  healthy.  This  dissemination  is  ac- 
complished largely  by  perspiration.  The  Englishman  is  accus- 


TO  DRAIN 

Fig.  74 — 'Galvanized  Iron  and  Wire  Air  Moistener. 

tomed  to  a  low  rate  of  perspiration,  the  American  to  a  higher 
rate,  the  difference  being  due  to  the  fact  that  each  has  grown 
up  in  or  become  susceptible  to  a  different  climate. 

Now,  regarding  the  probable  saving  in  fuel  by  changing  these 
conditions,  it  is  competently  estimated  that  25  per  cent,  of  the. 
cost  of  heating  is  expended  in  raising  the  temperature  within 
our  homes  from  60  to  70  degrees.  This  being  established  it  fol- 
lows that  one-fourth  of  the  cost  of  fuel  can  be  saved  by  main- 
taining the  temperature  of  the  rooms  at  60  degrees  and  pro- 
viding for  the  loss  in  moisture  (humidity)  due  to  heating  the 
air;  in  other  words,  by  keeping  the  percentage  of  humidity  at 
65  or  75.  The  result  will  be  a  sensible  temperature  within  the 
rooms  which,  if  no  thermometer  is  at  hand  to  consult,  will  seem, 
and  in  fact  is,  entirely  comfortable. 

How  may  we  provide  for  properly  moistening  the  air?  This 
question  naturally  follows  in  our  discussion  of  the  subject. 

There  are  several  methods  by  which  the  air  supply  of  a  warm- 
air  or  furnace-heating  system  may  be  moistened  and  made  humid. 
The  common  practice  of  placing  a  small  cast  iron  receptacle  in 


126 


AIR  MOISTENING 


the  side  of  a  furnace  casing,  called  a  "water-pan,"  "vapor-pan," 
etc.,  is  but  a  feeble  effort  in  this  direction,  and  it  does  not  amount 
to  anything  for  the  purpose  intended.  True,  the  water  in  this 
pan  evaporates  into  the  air  supply  of  the  furnace,  but  it  is  very 
much  the  same  as  would  be  the  effort  of  the  arid  dry  air  of  a 
desert  to  take  its  moisture  from  a  small  brook. 

The  cold  air  may  be  admitted  through  a  chamber  in  which 
are  a  number  of  compartments  filled  with  crushed  coke,  over 
which  small  streams  of  water  from  a  perforated  water  pipe 
trickle  down,  keeping  the  coke  wet.  A  drip-pan  at  the  bottom  may 
connect  with  an  overflow  pipe  leading  to  a  drain. 


iX)  J=>ijo£   3°  cffe 
Fig-  75 — The  Herr  Humidizer. 


Fig.  74  illustrates  this  method,  the  coke  being  broken  into  small 
pieces  and  held  in  a  galvanized  iron  and  wire  rack  inside  the 
boxing  at  the  cold-air  inlet. 

Another  method  is  the  spraying  of  the  air  by  means  of  one  or 
more  small  atomizers  or  sprays  playing  on  the  incoming  air. 

There  is  but  little  difference  as  to  whether  the  air  is  moistened 
before  or  after  it  is  heated,  except  that  moist,  humid  air  absorbs 
the  radiated  heat  better  than  the  dry  air.  Spray  nozzles  of 
brass  may  be  obtained  and  they  are  of  simple  construction.  The 
centrifugal  action  prevents  the  openings  from  clogging.  For  a 
job  of  any  considerable  size  or  importance  a  bricked-in  humidify- 
ing chamber  with  cemented  floor  properly  drained  may  be  pro- 
vided in  the  basement  and  water  pipes  with  sprays  be  placed 
in  this  chamber. 

An  apparatus  for  spraying  the  air,  after  it  has  been  heated. 


AIR  MOISTENING 


127 


known  as  the  Herr  Humidifier,  has  been  found  to  be  very  effec- 
tive and  is  strongly  recommended  by  those  who  have  tried  it. 
This  device  seems  to  us  to  be  worthy  of  careful  investigation 
on  the  part  of  the  furnace  man.  It  has  been  greatly  improved 
and  some  few  defects  in  the  original  apparatus  have  been  cor- 
rected. 


Fig.   76  —  Humidizer   Attached   to    Furnace    Casing. 


ig-  75  shows  a  view  of  the  humidizer  proper  —  the  spray 
nozzle  and  adjustments.  The  small  stream  of  water  passing 
through  the  apparatus  strikes  the  spoon  C  and  is  deflected  in 
the  form  of  a  fine  spray,  which  saturates  the  air  in  the  top  cas- 
ing of  the  furnace.  The  size  of  this  stream  of  water,  and  con- 
sequently the  amount  of  moisture  mixed  with  the  air,  is  regulated 
by  the  adjusting  bar  B. 

Fig.  76  shows  the  method  of  attaching  the  humidizer  to  the 
casing  top  of  the  furnace,  and  Fig.  77  shows  a  complete  installa- 
tion of  the  same,  with  an  apron  provided  to  utilize  the  drip  from 
the  spray  nozzle. 

We  believe  that  no  further  description  of  the  device  is  neces- 


128 


AIR  MOISTENING 


sary,  and  that  the  utility  of  it  will  be  apparent  to  every  practical 
furnace  man. 

The  hot  air  as  it  rises  to  the  top  of  the  casing  is  moistened 
by  the  fine  spray  of  water,  which  is  absorbed,  and  then  passes 
through  the  leader  pipes  to  the  rooms  above,  producing  balmy, 


Fig.  77 — Complete  Installation  of  Humidizer. 

natural  atmosphere.     Tests  have  shown  a  relative  humidity  of 
from  60  to  65  per  cent,  of  complete  saturation. 

Placing  the  Water  Pan 

The  feeble  effort  to  obtain  these  results  by  using  a  water  pan 


AIR  MOISTENING 


129 


in  connection  with  the  furnace,  we  all  no  doubt  are  familiar 
with.  The  pan  is  located  at  the  wrong  point  to  be  effective,  even 
to  a  small  degree.  The  water  should  be  above  the  source  of 
heat. 

A     much     more     effective     water     pan     may    be     made     by 
riveting    and    soldering    a    strip    of    galvanized    iron    around 


Fig.  78 — Sectional  Elevation  and  Plans  Showing  Proper  Location 
of  Water  Pan. 

the  inside  of  the  top  casing,  immediately  under  the  openings  for 
the  connection  of  hot  air  leader  pipes.  This  ring  should  be  from 
two  to  two  and  one  half  inches  wide  with  the  inside  edge  turned 
up  a  little  over  one-half  of  an  inch.  In  Fig.  78  the  sectional 
elevation  illustrates  the  idea  and  the  plan  above  shows  a  little 
cup  riveted  on  the  side  of  the  casing  as  a  device  for  filling  small 
holes  in  the  casing  connecting  with  the  pan  on  the  inside  of  the 
casing. 

The  Hygrometer 

To  properly  understand  the  relation  of  humidity  to  heating 
we  must  know  that  the  sensible  temperature  (that  is,  the  temper- 


130 


AIR  MOISTENING 


ature  felt  by  the  body)  corresponds  to  the  temperature  of  the 
wet  bulb  thermometer;  therefore,  the  dryer  the  air,  the  greater 
is  the  difference  between  the  actual  and  the  sensible  temperatures. 
We  measure  or  determine  the  temperature  and  humidity  of 
the  air  with  an  instrument  known  as  a  hygrometer  or  hygro- 


Fig.  79 — The  Hygrometer. 

phant.  On  this  instrument  two  standard  thermometers  are  pro- 
vided, one  (a  dry  bulb)  showing  the  temperature  of  the  air,  and 
the  other  (a  wet  bulb)  showing  the  temperature  due  to  evapora- 
tion (Fig.  79).  In  the  center  is  a  fixed  scale,  and  to  the  right 
of  this  is  mounted  a  cylinder  upon  which  is  inscribed  columns 


AIR  MOISTENING  131 

of  figures  with  headings  numbered  from  "i"  to  "22."  This 
cylinder  may  be  freely  turned  by  the  knob  shown  at  the  top  of 
the  instrument,  and  the  figures  appearing  at  the  top  of  the  col- 
umn represent  the  difference  in  the  reading  of  the  dry  and  the 
wet  bulb  thermometers.  Revolve  the  cylinder  until  this  number 
appears  at  the  top  and  note  the  number  opposite  the  figure  on 
the  fixed  scale  representing  the  reading  of  the  dry  bulb  thermo- 
meter. This  number  gives  the  percentage  of  humidity. 

For  example  (note  illustration),  the  dry  bulb  thermometer 
shows  70  degrees  and  the  wet  bulb  60  degrees.  70  —  60  =  10 
number  at  the  top  of  the  cylinder  which  has  been  revolved  until 
this  number  appears.)  Now  note  the  cylinder  number  opposite 
the  figure  70  on  the  fixed  scale.  It  is  56,  which  is  the  relative 
humidity  or  percentage  of  moisture  in  the  air,  according  to  the 
thermometer  readings.  This  is  a  most  interesting  as  well  as  in- 
structive instrument. 


CHAPTER  XIII 
RECIRCULATION  OF  AIR  IN  FURNACE  HEATING 


It  is  generally  recognized  that  many  of  the  objections  to  fur- 
nace heating  are  brought  about  by  reason  of  the  installation  of 
cheap,  unsatisfactory,  and  unsanitary  work,  or  through  the  ig- 
norance displayed  by  the  unskilled  man  in  laying  out  and  in- 
stalling the  job. 

We  will  consider  some  of  these  objections,  their  cause  and 
how  they  can  be  remedied  and  the  work  made  satisfactory. 
Probably  the  first  and  most  frequent  objection  heard  is  that  made 
to  the  condition  of  the  air  within  a  building  when  it  is  warmed 
by  a  hot  air  apparatus,  viz.,  that  it  is  overheated  and  "stuffy." 
The  frequency  of  this  fault  we  must  admit;  and  it  is  brought 
about  through  the  installation  of  too  small  a  furnace  and  the 
provision  of  too  small  an  area  for  the  cold  or  fresh  air  duct.  A 
further  source  of  complaint  is  found  in  the  quality  of  the  air 
supplied. 


Quality  of  Air 

Let  us  consider  for  a  moment  this  complaint  and  the  cause  of 
it.  If  a  certain  size  of  a  building  requires  the  consumption  of 
12  pounds  of  coal  per  hour  to  transmit  the  necessary  number  of 
heat  units  to  take  care  of  the  exposure  or  cooling  surfaces,  a 
certain  size  of  grate  will  be  required  to  properly  burn  this  amount 
of  fuel,  and,  in  its  turn,  the  heating  surfaces  of  the  furnace 
which  transmit  these  heat  units  to  the  air  passing  through  it, 
must  be  of  a  certain  area  if  these  surfaces  are  not  to  be  over- 
heated in  the  effort  of  transmission.  This  means,  for  example, 
that  should  12  pounds  of  coal  per  hour  be  burned  on  a  grate 
having  three  (3)  sq.  ft.  of  area,  the  rate  combustion  would  be  4 
pounds  of  fuel  per  sq.  ft.  of  grate  per  hour.  Assuming  that 
.from  each  pound  of  fuel,  8,000  heat  units  are  available  for  warm- 
ing purposes,  then  8,000  X  12  =  96,000  units  per  hour  will  re- 
sult from  12  pounds  of  fuel  burned  on  432  sq.  in.  of  grate. 

Supposing  that  a  furnace  having  but  288  sq.  in.  or  2  sq.  ft.  of 
grate  area  was  installed  to  warm  this  building,  the  attempt  to 


RECIRCULATION  OF  AIR 


133 


burn  the  fuel  required  on  the  reduced  grate  area  requires  so  high 
a  rate  of  combustion  that  the  air  passing  through  the  furnace 
is  overheated,  thereby  destroying  its  invigorating  qualities,  and 
making  it  unfit  to  breathe  and  "stuffy"  in  effect. 

Air  Outlet  Necessary 

Another  reason  for  this  condition  (stuffy  atmosphere)  is  due 
to  the  fact  that  many  furnace  men  are  trying  to  introduce  warm 


—  Pur  not  in  ~z^; — ~ 
circulation. 


Fig.  80 — Poor  Air   Circulation  when  Room  has   No  Outlet. 

air  into  a  room  which  has  no  air  outlet,  except  the  leakage  around 
windows  and  doors,  doubtless  overlooking  the  fact  that  only  as 
much  air  can  be  admitted  to  a  room  as  the  amount  which  passes 
out,  and  the  effort  to  heat  the  room  in  this  manner  makes  neces- 
sary such  an  increase  in  the  temperature  and  velocity  of  the  in- 
coming air  as  will  drive  it  into  the  rooms. 

Heating  Windward  Side 

Right  along  this  line  is  the  complaint  that  during  the  prevalence 
of  high  winds  it  is  impossible  to  heat  the  rooms  on  the  windward 
side  of  the  house.  This  complaint,  as  well  as  the  preceding  one, 
can  be  overcome  wholly  or  in  large  part  by  the  proper  recircula- 
tion  of  the  air  within  the  building.  Fig.  80  represents  a  closed 


134 


RECIRCULATION  OF  AIR 


room  without  air  outlets,  except  the  leakage  through  walls  and 
around  windows.  Note  the  manner  of  the  circulation  of  the 
air,  or  rather  the  fact  that  there  is  practically  no  circulation  of 
it.  Place  a  rotating  register  and  flue  as  indicated  by  Fig.  81  anil 
note  the  difference  in  the  movement  of  the  air. 

Supposing  the  room  is  on  the  side  of  the  house  most  exposed 
to  the  strong  winds  of  winter;  the  placing  of  a  rotating  register 
and  flue  along  the  outside  wall  of  the  room  will  do  much  t.-> 
improve  the  circulation  of  the  air  in  it,  and  consequently  the 
proper  warming  of  the  room.  Fig.  82  illustrates  this  condition. 


Fig.  81 — Perfect  Circulation  of  Air  when  Rotating  Register  and  Return 
Air  Flue  are  Employed. 

In  illustrating  our  discussion  of  furnace  heating,  we  have  for 
convenience  frequently  shown  floor  registers.  We  do  not  like 
floor  registers.  From  a  healthful  standpoint  they  are  bad,  as 
they  collect  dirt  and  organic  matter,  and  often  much  of  the  bad 
air  in  a  room  may  be  traced  to  the  filth  and  dirt  which  has  col- 
lected in  the  boxing  under  a  floor  register.  If  circumstances 
make  necessary  the  use  of  floor  registers,  the  face  should  be  lifted 
out  and  the  boxes  wiped  out  at  least  monthly  with  some  germ 
destroying  wash. 

Opposition  to  the  Method 

As  stated  in  a  recent  chapter,  there  are  some  people  identified 


RECIRCULATION  OF  AIR 


135 


with  furnace  manufacture  and  installation  who  advise  against 
the  recirculation  or  rotation  of  the  air  within  a  building.  These 
advocate  a  positive  method  of  ventilation  notwithstanding  the 
consequent  expense  to  be  incurred  in  bringing  about  this  desired 
condition. 

The  objection  to  the  recirculation  of  the  inside  air  seems  to 
be  based  entirely  upon  the  feeling  that  the  quality  of  the  air  is 
lowered  and  that  the  health  of  the  occupants  thereby  is  endan- 
gered. 

We  believe  that  the  filtration  of  air  through  outside  walls  and 
windows,  considered  with  the  fact  that  ordinarily  less  than  half 
a  dozen  people  inhabit  a  single  dwelling,  renders  the  contamina- 
tion of  the  air  to  the  point  of  stuffiness  next  to  impossible. 


Fig.  82 — Showing  Effect  of  High  Wind  Against  a  Building  Heated 
with  Hot  Air. 

On  occasions  when  a  social  function  is  given  and  a  considerable 
number  of  people  are  present,  the  return  air  registers  can  be 
closed  and  the  outside  air  used  exclusively.  This  is  also  true  in 
the  event  of  any  of  the  occupants  being  sick  or  affected  with  a 
contagious  disease. 

While  we  recommend  ventilation — and  plenty  of  it — the  fact 
remains  that  a  very  great  number  of  furnace  heating  plants  are 
installed  without  any  form  of  ventilation,  and  the  amount  of 
fresh  air  admitted  is  limited  because  of  conditions  stated  in  this 
article.  The  installation  of  return  air  ducts  with  rotating  registers 
in  the  principal  rooms,  will  aid  in  the  distribution  of  the  fresh 


136 


RECIRCULATION  OF  AIR 


air  admitted  through  the  cold  air  duct,  and  this  feature  will  not 
only  make  the  furnace  heat  more  positively,  but  will  distribute 
the  air  at  the  least  possible  expense  for  fuel. 

Obtaining  Best  Results 

The  furnace  by  itself  cannot  warm  the  building.  It  can  do 
nothing  more  than  warm  the  air,  and  it  is  up  to  the  furnace  man 
to  take  this  warm  air  and  provide  methods  for  its  carriage  and 
distribution. 


Division    in 
Co/cf  Air  Duct. 


5  w/ngifiQ    D  Q/njoc.  r&' 
Fig.  83 — Proper  Construction  of  Return  or  Recirculated  Air. 

The  failure  to  obtain  proper  results  when  the  recirculation 
feature  has  been  introduced  in  furnace  heating,  is  usually  found 
to  result  from  the  fact  that  poor  judgment  has  been  exercised 
by  the  furnace  man  who  has  not  fully  understood  the  method 
to  be  followed. 

Connecting  Duct 

Ordinarily  the  circulating  duct  should  not  be  connected  to  the 
casing,  or  to  the  cold  air  pit  of  the  furnace,  but  rather  to  the 


RECIRCULATION  OF  AIR  137 

cold  air  duct ;  and  dampers  should  be  arranged  in  such  a  manner 
that  return  air  or  fresh  air  may  be  used  at  will.  The  cord  or 
chains  operating  these  dampers  may  extend  to  a  convenient  place 
on  the 'first  floor.  Fig.  83  shows  the  method  of  connecting  the 
duct. 

We  recommend  to  the  furnace  man  that  he  study  the  methods 
of  return  air  circulation,  and  the  advantages  to  be  gained  from 
the  installation  of  such  a  system  when  properly  erected. 


CHAPTER  XIV 
AUXILIARY  HEATING  FROM  FURNACES 


When  warming  a  building  with  a  hot  air  furnace  it  frequently 
happens  that  there  are  some  rooms  or  portions  of  the  building 
which,  owing  to  structural  conditions  or  remote  location,  cannot 
well  be  warmed  in  the  regular  manner  with  hot  air. 

These  conditions,  which  would  interfere  with  the  running  of 
hot  air  pipes,  will  not  interfere  with  the  installation  of  hot  water 
piping,  and  therefore  several  methods  have  been  devised  of  com- 
bining a  hot  air  and  hot  water  heating  apparatus,  making  use  of 
but  one  fire  for  supplying  the  necessary  heat  for  both  systems. 

This  is  accomplished  by  installing  a  somewhat  larger  furnace 
than  would  be  required  for  hot  air  alone,  and  by  placing  a  coil 
of  pipe  in  the  fire  pot  of  the  furnace  or  suspending  above  the 
fire  a  hollow  casting,  called  an  auxiliary  heater,  through  which 
the  water  may  circulate  and  receive  the  heat.  The  hot  water 
circulating  through  the  coil  or  casting  is  distributed  through 
piping  to  one  or  more  radiators  located  within  the  rooms  to  be 
warmed. 

It  is  not  necessary  for  the  furnace  man  to  be  adept — that  is, 
thoroughly  versed — in  the  practice  of  steam  fitting  in  order  to 
successfully  install  combination  jobs  of  this  character. 


Computing  Size  of  Radiator 

Probably  the  first  knowledge  that  should  be  acquired  pertain- 
ing to  this  method  is  to  learn  how  to  compute  the  size  of  radiator 
necessary  to  warm  a  room.  This  is  determined  by  considering 
the  cooling  surfaces  of  the  room,  glass  and  exposed  wall,  much 
the  same  as  for  hot  air  heating.  The  following  simple  rule  will 
give  fairly  accurate  results : 

First — Ascertain  the  square  feet  of  glass  surface  (windows 
and  outside  doors). 

Second — Ascertain  the  square  feet  of  exposed  wall  surafce 
(outside  walls,  windows  not  deducted). 


AUXILIARY  HEATING 


139 


Third — Ascertain    the    cubical    contents    of   the   room   to   be 
warmed. 

Divide  the  glass  surface  by  2. 

Divide  the  exposed  wall  surface  by  20. 

Divide  the  cubical  contents  by  200. 


Fire  Pat   of 
Furnace 


rtetu 


rn 


Fig.  84— Plan  and  Elevation  of  Pipe  Coil, 


The  product  of  these  results  plus  60  per  cent.,  will  give  the 
amount  of  hot  water  radiation  necessary  to  warm  the  room  to 
70  degrees  in  zero  weather  with  the  water  at  a  temperature  of 
1 80  degrees  Fahr. 

If  the  furnace  contractor  is  in  the  habit  of  estimating  accord- 
ing to  loss  per  hour  of  heat  units,  he  may  determine  the  total 


140 


AUXILIARY  HEATING 


loss  for  the  room  in  heat  units  and  divide  this  sum  by  150;  this 
calculation  will  give  the  square  feet  of  radiation  required. 

Heating  Furnace  Required 

The  next  item  to  consider  is  the  amount  of  heating  surface 
to  be  provided  in  the  furnace  to  supply  the  radiation  required. 
This  heating  surface  may  take  the  form  of  a  pipe  coil  as  illustrated 
by  Fig.  84,  which  shows  a  plan  and  elevation  of  a  pipe  coil,  or 


Fig.  85 — Cast  Iron  Auxiliary  Heater. 

of  a  hollow  casting  as  illustrated  by  Figs.  85  and  86.  These  cast 
iron  auxiliary  heaters  are  made  in  a  variety  of  shapes  and  sizes. 
Each  square  foot  of  surface  in  the  pipe  coil  shown  by  Fig.  84  if 
placed  low  in  the  fire  pot,  so  that  the  hot  fire  comes  in  contact 
with  it,  will  supply  50  sq.  ft.  of  radiation  with  hot  water  at  180 
degrees  or  60  sq.  ft.  of  radiation  with  the  water  at  160  degrees 


Fig.  86— Another  Form  of  Cast  Iron  Auxiliary  Heater. 

at  the  radiator.     If  the  coil  is  suspended  above  the  fire  it  will 
supply  from  25  to  30  sq.  ft.  of  radiation. 

Should  a  hollow  casting  similar  to  that  illustrated  by  Figs.  85 
or  86  be  employed  as  heating  surface  in  the  furnace,  it  is  sus- 
pended above  the  fire  and  varies  in  efficiency  from  20  sq.  ft.  of 
radiation  supplied  for  each  square  foot  of  heating  surface  in 


AUXILIARY  HEATING 


141 


O^erf/ow 


Furngce. 


Fig.  87 — Typical  Arrangement  of  an  Auxiliary  Hot  Water 
Heating  Apparatus. 


142 


AUXILIARY  HEATING 


•  Ovzrf/ow. 


Fig.  88 — Domestic  Hot  Water  Supply  from  Furnace. 


AUXILIARY  HEATING 


Fig.  89— Overhead  Piping  of  Auxiliary  Hot  Water  System. 


i/l/l  AUXILIARY  HEATING 

the  casting,  to  possibly  25  or  30  sq.  ft.,  depending  upon  how 
much  of  the  casting  is  direct  heating  surface  and  how  far  above 
the  fire  it  may  be  located. 

Installing  the  Apparatus 

The  method  of  installing  the  piping  and  of  connecting  to  the 
radiators  has  more  to  do  with  the  success  or  failure  of  a  job 
of  this  character  than  the  construction  of  any  other  part  of  the 
system.  Fig.  87  is  a  typical  illustration  of  an  auxiliary  hot 
water  heating  apparatus  and  shows  two  radiators  supplied  by 
a  coil  in  the  furnace. 

Note  the  small  tank  at  the  top  of  the  system.  This  is  called  an 
expansion  tank.  Water  when  heated  from  32  to  212  degrees  (the 
boiling  point)  expands  1/25  of  its  volumne,  and  unless  some 
provision  were  made  for  taking  care  of  this  expansion  the 
system  would  overflow  when  heated,  and  when  the  water  in  the 
system  was  again  cooled  and  contracted,  the  upper  part  of  the 
system  would  fill  with  air  which  would  interfere  with  the  cir- 
culation. The  tank  should  be  located  in  such  a  position  that 
the  bottom  of  it  is  well  above  the  top  of  the  highest  radiator 
and  the  pipe  connecting  the  tank  with  the  system  (called  the  ex- 
pansion line)  should  be  connected  as  indicated  on  the  illustration. 
Ordinarily  an  expansion  tank  of  from  eight  to  twelve  gallons' 
capacity  is  sufficient  for  a  combination  job.  An  eight  gallon  tank 
will  take  care  of  200  to  250  square  feet  of  radiation  and  a  twelve 
gallon  tank,  300  to  400  square  feet. 

The  size  of  pipe  to  be  used  in  connecting  to  the  radiators  is 
determined  by  the  size  of  each  radiator. 

A  I  inch  pipe  will  supply  35  or  40  square  feet  of  radiation 
on  the  first  floor  above  the  furnace  or  60  to  70  square  feet  on 
the  second  or  third  floor.  In  like  manner  a  ij4  inch  pipe  will 
supply  60  to  70  square  feet  on  the  first  floor,  or  90  to  no  square 
feet  on  the  second  or  third  floor.  A  \y2  inch  pipe  will  supply 
100  to  no  square  feet  on  the  first  floor  or  150  to  160  square  feet 
on  the  second  or  third  floor,  and  the  main  flow  pipe  from  the 
furnace  must  have  an  area  equal  to  the  combined  area  of  all 
radiator  connections. 

An  installation  of  this  kind  is  known  as  a  circulating  job,  and 
no  radiators  or  pipes  are  valved.  The  radiators  are  employed 
in  exactly  the  same  manner  as  would  be  a  storage  tank  for  do- 
mestic hot  water  use.  If  the  radiators  were  valved  and  the  valves 
should  be  closed,  the  excess  of  heating  surface  would  boil  the 
water  in  the  system.  The  cooling  surface  of  the  radiators  pre- 
vents this  happening  when  they  are  in  service. 

Another  method  of  installing  an  auxiliary  hot  water  apparatus 
is  illustrated  by  Fig  88,  which  shows  a  cast  iron  auxiliary  heater 


AUXILIARY  HEATING  145 

employed  within  the  furnace.  The  piping  system  shown  in  the 
illustration  indicates  another  of  the  several  methods  that  may  be 
used.  The  expansion  tank  is  connected  from  the  high  point  of 
the  system,  and  therefore  air  valves  on  the  radiators  are  not  re- 
quired, as  all  air  in  the  system  passes  to  the  atmosphere  through 
the  expansion  tank. 

It  is  well  that  the  furnace  man  should  become  acquainted  with 
the  methods  of  estimating  and  installing  auxiliary  heating  systems, 
as  they  are  frequently  desired  by  the  house  owner. 

Auxiliary  heaters  are  frequently  employed  for  furnishing  hot 
water  for  domestic  use  and  are  installed  in  connection  with  the 
kitchen  boiler  or  storage  tank. 

The  piping  is  usually  cross-connected  with  that  from  the  kit- 
chen range  and  valved  so  that  the  auxiliary  heater  may  be  cut 
out  during  the  summer  season  when  the  furnace  is  not  in  use. 
Fig.  89  illustrates  an  installation  of  this  kind. 

An  expansion  tank  is  not  required  on  a  system  of  this  kind, 
as  the  water  is  used  under  pressure,  and  a  job  of  this  character 
would  be  designated  as  a  pressure  system. 

The  heating  surface  required  in  the  furnace  auxiliary  heater 
is  i  square  foot  for  each  20  gallons  of  water  in  the  storage  tank 
or  kitchen  boiler. 


CHAPTER  XV 

TEMPERATURE  REGULATION  AND  FUEL  SAVING 

DEVICES 

The  value  of  a  good  temperature  regulator  seems  to  be  neither 
understood  nor  appreciated  by  the  heating  contractor. 

What  the  governor  is  to  an  engine  the  thermostat  is  to  a  fur- 
nace. The  governor,  attached  to  an  engine,  prevents  the  engine 
from  "running  away''  or  speeding  when  the  load  or  work  it  is 
doing  is  suddenly  lightened, — in  other  words,  it  regulates  the 
speed  of  the  engine  automatically,  preventing  useless  waste  and 
possible  danger. 

The  thermostat  or  temperature  regulator,  attached  to  a  furnace, 
prevents  the  overheating  of  the  building  and  consequent  waste 
of  fuel.  It  also  prevents  possible  damage  due  to  overheating  the 
furnace. 

There  are  some  features  of  temperature  regulation  which,  if 
brought  to  the  attention  of  the  house  owner  in  a  convincing 
manner,  should  effect  a  ready  sale  of  an  appliance  of  this  nature, 
as  little  necessity  exists  for  argument  on  the  part  of  the  furnace 
man  when  such  features  are  made  known. 

We  have  mentioned  the  saving  in  fuel,  which  may  be  effected 
by  a  system  of  thermostatic  control.  The  health  of  the  occupants 
of  the  home,  and  the  comfort  experienced,  may  also  be  considered 
as  desirable  features  of  temperature  regulations. 

A  brief  argument  in  favor  of  the  thermostat  may  be  made  by 
considering  these  three  features : 

(a)  Saving  in  fuel  and  consequent  low  cost  of  maintenance. 

(b)  Healthfulness  due  to  uniformity  of  temperature. 

(c)  Personal  comfort  as  a  result  of  having  a  watchman  (ther- 
mostat)  in  charge  of  the  furnace,  to  open  or  close  the  draught 
doors  at  the  required  moment. 

Briefly  stated,  the  work  to  be  performed  by  the  furnace  may 
be  considered  as  follows: 

Consulting  a  table  of  temperatures  compiled  by  the  United 
States  Government,  giving  maximum  and  minimum  temperatures 
of  some  thirty  cities,  and  covering  all  sections  of  this  country 
and  Canada  where  heat  is  required  in  winter,  we  find  that  the 
average  number  of  degrees  the  temperature  is  to  be  raised  arti- 
ficially is  80°.  In  Charleston,  S.  C.,  it  is  47°,  while  in  Duluth, 
Minn.,  it  is  108°. 


TEMPERATURE  REGULATION  147 

The  average  winter  temperature  for  the  period  we  call  "the 
heating  year''  is  a  little  under  40°  F.  As  we  have  already  re- 
marked, in  this  country  we  demand  a  temperature  of  70°  within 
our  homes,  and  therefore  we  must  raise  the  temperature  approx- 
imately, an  average  of  30°.  It  requires  just  so  much  heat,  or 
the  expenditure  of  just  so  many  heat  units  to  produce  this  result, 
and  for  every  degree  above  70°,  shown  by  the  thermometer, 
there  is  a  loss  of  fuel  in  a  direct  ratio  to  the  increase  in  tempera- 
ture, and  this  loss  at  a  low  estimate  is  25  per  cent. 

Of  the  healthfulness  due  to  a  uniform  temperature,  it  seems 
necessary  only  to  state  that  all  physicians  and  scientists,  who 
have  made  a  careful  study  of  the  subject,  report  and  agree,  that 
next  to  the  proper  ventilation  of  our  homes,  a  uniform  degree 
of  heat  is  essential  to  the  good  health  of  the  occupants.  We 
are  safe  in  saying  that  few  colds,  and  few  of  the  more  serious 
diseases  so  prevalent  in  winter,  will  be  experienced,  if  a  uniform 
temperature  is  maintained  in  the  home. 

Finally  comes  the  question  of  personal  comfort.  It  has  been 
stated  that  this  is  the  age  of  personal  comfort,  "the  automatic 
age"  and  "the  electrical  age."  It  is  now  that  the  furnace  man 
may  deliver  the  solar  plexus  blow — the  final  argument. 

The  period  when  artificial  heat  is  necessary  comes  as  regularly 
as  the  time  when  food  is  necessary  to  sustain  us,  and  the  per- 
sonal comfort,  due  to  the  work  of  the  thermostatic  watchman 
in  attending  the  furnace,  cannot  well  be  calculated. 

We  may  repeat  what  we  had  occasion  some  time  ago  to  re- 
mark regarding  the  thermostat.  "It  is  a  boon  to  the  busy  man 
and  a  delight  to  the  lazy  man,  and  is  more  than  self-sustaining, 
paying  for  itself  in  a  season  or  two,  after  which  it  earns  money 
for  the  owner  at  a  rate  never  excelled  by  the  best  savings  insti- 
tution." 

Arguments  and  facts  such  as  these,  when  brought  to  the  at- 
tention of  the  users  of  hot  air  furnaces,  should  make  possible 
the  sale  of  a  good  many  thermostats,  and  materially  add  to  the 
business  of  the  furnace  dealer. 

Fuel  Saving  Appliances 

Each  pound  of  anthracite  coal  when  used  for  fuel  in  a  furnace 
gives  off  approximately  14,500  heat  units.  About  10,000  of  these 
are  available  for  heating  purposes,  the  remainder  being  utilized 
principally  in  warming  the  air  in  the  chimney  flue  to  produce 
sufficient  draft  to  carry  off  the  smoke  and  products  of  combus- 
tion. 


148  TEMPERATURE  REGULATION 

In  considering  the  question  of  economy  in  fuel  we  may  say 
first  of  all  that  it  is  a  poor  policy  to  select  a  furnace  with  a  grate 
so  small  that  it  is  necessary  to  keep  the  fire  in  a  continual  state 
of  activity  to  properly  heat  the  building.  The  frequent  "stirring 
up"  of  the  fire  by  a  shaking  of  the  grate  and  the  addition  of 
more  fuel  are  as  wasteful  as  they  are  unnecessary.  With  a  fur- 
nace having  a  grate  of  adequate  size,  or  perhaps  a  little  larger 
than  is  absolutely  essential,  the  very  best  result  is  obtained  in 
the  way  of  economy,  provided  the  heater  is  fired  in  an  intelligen! 
manner.  There  is  great  waste  in  intermittent  firing.  By  this  we 
mean  the  opening  of  the  draft  door  of  the  furnace,  forcing  the 
fire  to  greater  activity  and  allowing  the  building  to  become  over- 
heated, requiring  the  opening  of  the  windows.  The  coal  should 
be  permitted  to  burn  just  enough  to  give  ofif  the  required  heat 
units  to  keep  the  building  warmed  to  the  desired  temperature. 

This  can  be  accomplished  only  by  the  use  of  some  good  system 
of  temperature  regulation  which  will  automatically  control  the 
fire  by  opening  and  closing  the  draft  and  check  dampers  of  the 
heater.  The  appliances  to  perform  this  work  are  called  "regu- 
lators" or  "thermostats,"  and  there  are  many  good  and  reliable 
kinds  to  be  had. 

It  will  be  impossible  here  to  illustrate  and  describe  all  of  the 
various  makes,  and  therefore  we  shall  select  several  of  those 
most  commonly  used,  showing  the  manner  by  which  they  ac- 
complish the  service  demanded  of  them  and  for  which  they  are 
intended.  It  will  be  of  interest  to  our  readers  to  know  some- 
what of  the  history  of  temperature  regulation,  or  of  the  inven- 
tion and  application  of  methods  for  automatically  controlling 
the  drafts  of  a  heating  apparatus.  A  device  for  this  purpose 
was  invented  by  a  Frenchman,  named  Du  Moucelle,  of  Paris, 
in  1853.  The  first  practical  temperature  regulator  in  this  country 
was  invented  in  1883  by  W.  S.  Johnson,  of  Milwaukee,  Wis., 
who  placed  it  on  the  market  in  1884.  Some  four  years  later  W. 
P.  Powers  (then  in  the  plumbing  and  steam  fitting  business), 
of  La  Crosse,  Wis.,  devised  a  vapor  thermostat  for  operating  the 
draft  doors  of  a  furnace. 

At  about  this  time  (1885)  an  electric  thermostat  was  devised 
in  Minneapolis,  Minn.,  and  later  put  on  the  market  by  the  Elec- 
tric Heat  Regulator  Company.  This  regulator  in  an  improved 
form  we  shall  later  illustrate  and  describe. 

These  regulators  and  thermostats  have  been  followed  by  num- 
erous other  varieties,  all  of  which  may  be  divided  into  two  gen- 
eral classes,  viz.,  electric  and  non-electric.  In  the  list  of  the 


AND  FUEL  SAVING  149 

electric  thermostats  and  regulators  are  included  the  Minneapolis, 
Jewell,  Beckam,  Beers,  Honeywell,  and  among  the  non-electric 
we  find  the  Johnson,  Powers,  Regitherm,  Howard,  National,  and 

others. 

Many  of  the  automatic  regulators  en  the  market  are  used 
principally  for  the  control  of  steam  and  hot  water  heating  ap- 
paratus, for  the  control  of  gas  and  liquids,  and  for  the  control 
of  water  and  other  liquids  in  tanks.  This  latter  is  styled  "tank 
control." 

We  shall  consider  and  describe  only  those  which  are  especially 
used  for  the  control  of  a  furnace — those  whose  operation  is  di- 
rectly governed  by  the  temperature  of  the  air  within  a  room  of  a 
residence  or  similar  building. 

Electric  Regulators 

The  Minneapolis,  Honeywell,  Jewell,  Beckam  and  Beers  regu- 
lators make  use  of  devices  for  the  electric  control  of  the  ap- 
paratus, which  are  quite  similar  in  the  operation  performed.  This 
appliance  is  placed  on  the  wall  of  one  of  the  principal  living 
rooms  of  the  residence.  Fig.  90  shows  the  device  as  used  with 
the  Minneapolis  regulator.  Fig  91  shows  the  device  with  its 
shield  or  cover,  on  which  is  mounted  a  mercury  thermometer. 
It  consists  of  a  frame  holding  a  piece  of  metal  in  the  form  of 
a  loop  or  ring  with  a  tongue  or  strip  of  metal  suspended  from 
the  bottom  of  the  loop.  One  end  of  the  loop  is  attached  to  the 
frame,  the  other  end  and  the  suspended  tongue  hanging  free. 
The  slightest  change  of  temperature  will  expand  or  contract  the 
ring  causing  a  side  movement  of  the  suspended  tongue  or  arm. 
An  electric  battery  (consisting  of  two  or  three  cells  of  dry  bat- 
tery) is  used  to  generate  the  electric  current  through  two  wires, 
which  are  attached  to  posts  or  pins  located  one  on  either  side  of 
the  suspended  arm.  Small  thumb-screws  or  pins  are  set  in  these 
posts,  so  adjusted  as  to  allow  the  points  to  almost  touch  the  sus- 
pended blade.  As  the  temperature  of  the  room  rises  the  loop 
expands  throwing  the  blade  against  one  set  screw  closing  the  . 
electric  circuit  and  operating  the  motor  or  driving  power  of  the 
thermostat,  which,  in  turn,  operates  the  draft  of  the  furnace  by 
closing  the  draft  door  and  opening  the  check  door.  When  the 
temperature  of  the  room  has  lowered  the  blade  gradually  works 
over  against  the  pin  on  the  opposite  side  of  the  frame.  The 
action  of  the  motor  is  then  reversed  and  the  draft  door  is  opened 
and  the  check  damper  closed. 

The  driving  power  or  motor  of  the  Minneapolis,  shown  by 
Fig.  92  consists  of  a  strong  spring  within  the  motor  which  is 


150 


TEMPERATURE  REGULATION 


wound  up  like  the  spring  of  a  clock.  Two  arms  or  cranks  point- 
ing in  opposite  directions  work  the  chains  connected  with  th<> 
draft  doors. 


Fig.  90 — Thermostat 
with   Screen  Removed. 


Fig.  91 — Thermostat 
with  Screen  Attached. 


The  motor  of  the  Beckam,  Fig.  93,  and  also  that  of  the  Honey- 
well regulator,  is  operated  by  a  ball  weight  attached  to  a  chain 
which  is  run  over  a  sprocket  pulley  wheel  and  is  wound  or  drawn 
up  in  much  the  same  manner  as  the  weights  of  an  old-fashioned 
Swiss  clock. 

The  Beers  regulator  uses  two  weights,  each  hung  by  a  pulley 
wheel,  as  shown  by  Fig.  94,  which  figure  also  illustrates  in  a 
general  way  the  method  of  adjusting  the  chains  to  the  draft  of  the 
furnace. 

Non-Electric  Regulators 

We  will  now  consider  some  of  the  non-electrics,  among  which 
are  found  the  Powers  and  Regitherm.  There  are  other  non- 
electric thermostats  in  the  market,  many  of  them  being  used 
only  with  a  steam  or  a  hot  water  heating  apparatus.  Those 
mentioned  here  will  be  sufficient,  however,  to  show  some  of  the 
methods  employed. 


AND  FUEL  SAVING 


The  Powers  thermostat  operates  on  the  vapor  principal.  On 
the  wall  of  one  of  the  living  rooms  of  a  residence  is  located  a 
metal  disc  composed  of  two  plates  fastened  together  at  the  edge. 
This  is  about  12  inches  in  diameter,  and  about  I  inch  thick. 


Fig.  9 


The  metal  of  the  plate  is  spun  in  corruga- 
tions to  give  flexibility.  A  liquid  is  placed 
within  the  disc  which  will  vaporize  at  a 
very  low  temperature,  and  which  gen- 
erates a  pressure  within  the  disc.  Fas- 
tened to  the  back  of  the  disc,  and  open- 
ing into  it,  is  a  small  hollow  tube. 
Through  this  tube  the  pressure  of  the 
vapor  is  conveyed  to  a  diaphragm  motor 
located  above  the  furnace.  The  pressure 
en  the  disc  of  the  diaphragm  lowers  the 
arm,  to  the  end  of  which  the  draught  doors  are  connected  by 
chains.  This  movement  closes  the  draught  door  and  opens  the 
check  damper  of  the  furnace,  checking  the  fire.  As  soon  as  the 
room  cools,  the  pressure  on  the  diaphragm  is  removed.  The 
arm  of  the  motor  then  returns  to  its  former  position,  closing 
the  check  and  opening  -the  draught  door  of  the  furnace. 

Fig.  95  shows  the  diaphragm  motor  of  the  Powers  regulator 
and  the  method  of  attaching  same  to  the  furnace.  It  is  held  in 
position  above  the  furnace  by  a  pipe  rod,  attached  to  ceiling.  The 
small  hollow  pipe,  conveying  the  power  from  the  thermostat  to  the 
motor,  can  be  seen  as  it  passes  through  the  space  between  floor 
and  ceiliing,  and  thence  along  the  ceiling  to  point  above  the 
motor,  where  it  drops,  and  is  connected  into  the  upper  side  of 
the  diaphragm. 

The  Regitherm  is  a  temperature  regulating  device,  entirely 
different  in  principle  from  any  of  the  others.  The  thermostat  and 
motor  are  combined  into  a  single  instrument  which  may  be  called 


I52  TEMPERATURE  REGULATION 

a  thermal  motor.  Fig.  96  will  give  a  general  idea  of  its  appear- 
ance. The  vital  part  or  motor  consists  of  a  closed  metal  bellows, 
so  constructed  that  it  readily  expands  and  contracts  along  the 
line  of  its  axis.  A  cross  section  of  the  folds  is  roughly  shown 
by  Fig.  97.  The  theory  of  this  construction  is  that  strain  is 
brought  on  the  point  marked  A,  and  no  bending  occurs  at  B, 
which  is  the  point  of  greatest  weakness. 


Fig.  94— Beers  Regulator  Attached. 


This  bellows  contains  a  quantity  of  volatile  liquid,  extremely 
sensitive  to  minute  variations  of  temperature.  The  bellows  is 
rigidly  attached  at  one  end  to  the  frame  work,  and  at  the  other 
to  a  lever,  which  is  moved  up  and  down  by  the  expansion  and 
contraction  of  the  bellows. 

A  unique  feature  of  the  device  is  the  fact  that  the  power  to 
adjust  the  dampers  is  derived  entirely  from  the  changes  in  tem- 
perature of  the  air  of  the  room  in  which  the  Regitherm  is  lo- 
cated, and  the  movement  of  the  bellows  is  communicated  to  the 


AND  FUEL  SAVING 


153 


dampers  of  the  furnace  by  means  of  a  small  steel  wire  or  cable 
passing  over  pulleys  and  connected  to  a  lever  above  the  furnace. 

Unlike  most  of  the  temperature  regulators,  the  Regitherm  does 
not  accomplish  the  desired  result  by  the  alternate  opening  and 
closing  of  the  dampers.  Some  intermediate  position  is  assumed, 
and  a  slight  shifting  of  the  dampers  takes  place  whenever  the 
temperature  conditions  in  the  rooms  above  are  changed.  It  may 
be  set  to  control  the  temperature  at  any  point  between  60  and 
80  degrees. 


Fig.  95 — Diaphragm  Motor  Attached  to  Furnace. 


We  have  given  somewhat  of  the  history  of  temperature  regula- 
tion, and  quite  fully  described  some  of  the  various  apparatus,  in 
order  that  the  furnace  man  may  post  himself  regarding  the  sub- 
ject and  also  gain  a  general  knowledge  of  the  apparatus  used, 
and  the  methods  adopted  to  automatically  control  the  work  of 
the  furnace. 

It  is  a  part  of  the  furnace  business  which  has  been  neglected, 
and  for  no  apparent  reason.  The  average  type  of  regulator  is 
easily  installed,  reasonable  in  price,  and  its  sale  can  be  made  a 
profitable  and  desirable  adjunct  to  the  furnace  business. 


154 


TEMPERATURE  REGULATION 


The  value  of  a  good  temperature  regulator  seems  to  be  neither 
understood  nor  appreciated  by  the  heating  contractor. 

What  the  governor  is  to  an  engine  the  thermostat  is  to  a  fur- 
nace. The  governor,  attached  to  an  engine,  prevents  the  engine 


Fig.  96 — Thermal    Motor. 

from  "running  away"  or  speeding  when  the  load  or  work  it  is 
doing  is  suddenly  lightened, — in  other  words,  it  regulates  the 
speed  of  the  engine  automatically,  preventing  useless  waste  and 
possible  danger. 


Fig.  97 — Principle  of  Constructing  Thermal   Motor. 

The  thermostat  or  temperature  regulator,  attached  to  a  fur- 
nace, prevents  the  overheating  of  the  building  and  consequent 
waste  of  fuel.  It  also  prevents  possible  damage  due  to  over- 
heating the  furnace. 


AND  FUEL  SAVING  155 

By  selling  and  attaching  temperature  or  automatic  damper 
regulators  the  furnace  man  not  only  provides  the  means  of  safety 
and  economy  to  the  owner,  but  in  so  doing  adds  another  branch 
to  his  business  which  will  materially  increase  the  profits  of  the 
same  each  season. 

How  to  Sell  Thermostats 

We  have  mentioned  three  arguments  in  favor  of  temperature 
regulation, — economy,  healthfulness  and  comfort.  These  fea- 
tures of  economy  and  satisfaction  are  prominent  factors  to  be 
considered. 

Thermostats  are  easily  sold  when  their  merits  are  brought 
to  the  attention  of  house  owners  in  the  right  manner.  Practically 
no  argument  is  necessary  on  the  part  of  the  heating  contractor 
to  effect  the  ready  sale  of  a  thermostat  when  the  convenient  and 
economical  features  above  referred  to  are  made  known  to  him. 

Considering  the  first  feature,  that  of  economy,  we  may  say 
that  one  shovelful  of  coal  saved  daily  for  the  heating  season  will 
approximate  one  ton  saved  for  the  season.  Intermittent  firing 
or  coaling  of  the  heating  apparatus  is  one  of  the  wasteful  items 
to  contend  with.  Remembering  how  frequently  it  has  been  neces- 
sary to  coal  the  furnace,  due  to  forgetfulness  in  leaving  the  draf \ 
doors  open,  the  owner  will  readily  understand  the  situation  when 
the  statement  is  made  that  the  use  of  any  good  system  of  tem- 
perature regulation  will  save  from  one-quarter  to  one-third  of 
the  fuel  ordinarily  consumed  when  operating  the  furnace  with- 
out such  a  device. 

How  can  we  show  the  owner  that  this  saving  is  possible  ?  There 
should  be  no  trouble  in  proving  to  the  owner  that  intermittent 
firing  is  costly.  We  have  already  referred  to  the  temperature 
bulletin  issued  by  the  U.  S.  Government,  which  shows  a  wide 
variance  of  the  demands  for  heat;  it  being  necessary  in  certain 
portions  of  the  extreme  north  to  raise  the  temperature  frequently 
through  80  to  100  degrees,  while  in  southern  cities,  for  instance 
in  Charleston,  S.  C,  it  is  necessary  to  raise  the  temperature  an 
average  of  47  degrees.  When  we  consider  that  a  change  of  10, 
20  or  30  degrees,  up  or  down  in  the  temperature,  frequently 
takes  place  within  a  few  hours  time  and  that  the  regulator  will 
condition  the  fire  in  the  furnace  to  accommodate  this  sudden 
change,  we  can  understand  that  automatic  regulation  will  effect 
a  great  saving. 

In  this  country  a  week  of  solid  cold  weather  is  the  exception 
rather  than  the  rule.  In  Canada  the  week  of  mild  weather  in 
winter  is  the  exception  rather  than  the  rule.  Consequently,  we 
have  very  much  more  need  of  temperature  regulation  in  the 
United  States  than  they  have  in  Canada. 


156  TEMPERATURE  REGULATION 

Of  the  second  feature,  healthfulness,  we  need  add  but  lit- 
tle in  addition  to  what  has  already  been  said,  as  all  who  have 
investigated  the  subject  know  the  desirability  of  keeping  the 
temperature  uniform  within  the  home.  Uniformity  of  tem- 
perature is  considered  as  necessary  as  is  ventilation  or  heat- 
ing. 

The  next  feature  to  consider  is  personal  comfort,  and  here 
is  the  chance  for  the  delivery  of  a  telling  and  conclusive  argu- 
ment. In  business,  as  well  as  in  pleasure,  this  age  is  spe- 
cialized with  automatic  devices.  Think  of  the  number  of 
automatic  devices  which  increase  the  efficiency  of  business, 
and  the  intensity  of  pleasure.  Then  why  not  automatic  per- 
sonal comfort?  Doesn't  that  sound  good?  The  heating  sea- 
son comes  just  as  regularly  each  year  as  does  dinner  time  each 
day.  The  comfort  and  convenience  of  having  an  automatic 
watchman  in  charge  of  the  furnace  to  open  and  close  the 
drafts  as  required,  is  an  argument  which  ought  to  appeal  as 
well  to  the  busy  man  as  to  the  seeker  after  personal  comfort. 

The  Cost  of  Heat  Regulation 

Automatic  temperature  regulating  devices  cost  the  owner 
from  twenty-five  to  fifty  dollars,  according  to  the  character 
and  make  of  the  device.  At  the  price  named  there  is  a  fair 
profit  to  the  furnace  contractor  for  installing  the  same. 

As  a  matter  of  fact,  the  thermostat  really  costs  the  house 
owner  nothing,  for  it  saves  many  times  the  interest  on  the 
investment  each  season  until  the  saving  made  pays  the  cost 
of  the  installation,  after  which  it  earns  money  for  the  owner 
at  a  greater  rate  than  any  ordinary  business  investment  he 
may  have.  It  would  seem  then  that  the  cost — whether  twenty- 
five  or  fifty  dollars — is  not  prohibitive.  In  fact,  it  should  not 
be  considered  when  the  economical,  healthful  and  comfort- 
able features  brought  about  by  its  use  are  known  and  appre- 
ciated. 

How  to  Attach  Thermostats 

It  is  possible  that  the  failure  to  sell  and  install  more  thermo- 
stats is  due  to  fear,  on  the  part  of  the  heating  contractor,  that 
he  may  not  be  able  to  install  the  apparatus  correctly. 

If  it  is  a  fact  that  the  furnaceman  is  letting  slip  this  oppor- 
tunity to  better  his  work  and  add  to  his  profits  through  ignor- 
ance of  the  construction  and  method  of  installation  of  auto- 
matic heat  regulators,  a  very  little  investigation  of  the  subject 
will  show  that  the  average  thermostat  is  quickly  and  easily 
attached  and  adjusted. 


AND  FUEL  SAVING 


157 


All  thermostats  have  a  positive  and  a  negative  action  of  the 
motor  or  other  mechanism  which  controls  the  drafts.  This 
positive  or  negative  action  of  the  motor  or  other  mechanism 
opens  or  closes  the  draft  and  check  doors  automatically  in  con- 
junction with  each  other,  the  check  damper  opening  as  the  draft 
door  closes,  and  vice-versa ;  therefore  no  matter  what  type  of  a 
thermostat  is  to  be  installed  it  must  be  attached  in  such  a  manner 
that  the  draft  and  check  doors  will  operate  together,  and  to 
accomplish  this  result  the  chain  connections  to  the  doors  are  run 
over  pulleys  hung  from  the  joists  above  the  furnace  and  con- 
nected in  the  most  simple  manner. 


1  MOTOR 


ioo\ 


j 


CHECK 


Fig.  98 — Method  of  Attaching  a  Minneapolis  Regulator. 


Fig.  98  illustrates  a  method  of  connecting  the  Minneapolis 
Regulator.  The  driving  power  of  this  thermostat  is  a  motor 
operated  by  a  strong  spring  and  its  approximate  location  is  shown 
on  the  sketch.  Note  that  in  order  to  prevent  the  sagging  of 
chains  between  pulleys  a  wire  is  employed,  to  which  the  ends  of 
chains  running  over  or  through  the  pulleys  are  attached. 

Fig.  99  illustrates  the  manner  of  attaching  a  Honeywell  Regu- 
lator to  a  hot  air  furnace.  The  driving  power  of  this  regulator 


158 


TEMPERATURE  REGULATION 


is  a  motor  operated  by  a  weight.  This  weight  is  suspended  by 
a  chain,  the  links  of  which  fit  over  the  teeth  of  a  sprocket,  and 
the  winding  up  of  the  motor  consists  of  pulling  up  the  weight 
much  as  one  would  wind  an  old  fashioned  grandfather's  clock. 

Practically  all  of  the  so-called  electric  thermostats  make  use 
of  two  cells  of  dry  battery  for  supplying  the  current  for  con- 
trolling the  motor,  and  through  this  the  drafts  of  the  furnace. 


CABLE  JO 

THERMOSTAT 

MOTOR 


Fig.  99 — Method  of  Attaching  a  Honeywell  Regulator. 

Three  copper  wires  of  a  size  simiar  to  that  used  for  connecting 
door  bell  batteries  are  insulated  in  red,  white  and  blue  covering 
and  encased  in  the  form  of  a  single  cable.  These  wires  are 
attached  to  various  parts  of  the  thermostat  where  directed,  and 
the  cable  then  extends  down  to  the  basement,  and  to  the  motor 
of  the  regulator,  where  the  wires  are  separately  connected  to 
certain  parts  of  the  motor. 

The  cells  of  dry  battery  should  be  connected  together  as 
shown  by  Fig.  100  which  represents  the  top  of  the  cells.  The 
white  covered  wire  in  the  cable  should  be  attached  to  the  bat- 
teries as  indicated  on  the  sketch.  The  wiring  of  all  thermostats 
and  regulators  is  practically  the  same,  and  the  regulator  is  now 
ready  for  adjustment  and  attachment  to  the  furnace. 


AND  FUEL  SAVING 


159 


In  this  connection  we  desire  to  speak  of  the  check  damper 
of  the  furnace.  The  check  damper  door  of  many  furnaces  is  in- 
accessible for  use  with  a  regulator  and  also  is  frequently  not  of 
proper  construction.  When  this  is  found  to  be  the  case  it  is  best 


WIRES    TO  MOTOR- 


Fig.  100 — Method  of  Connecting  Dry  Battery. 

to  employ  a  specially  designed  balanced  check  damper,  as  illus- 
trated by  Fig.  101.  This  check  damper  should  not  take  the  place 
of  the  regular  smoke  pipe  damper,  which  should  continue  to  be 
used  and  which  should  be  located  at  a  point  in  the  smoke  pipe 
between  the  furnace  and  the  check  damper. 

It  would  be  quite  impossible  in  a  brief  article  to  describe  the 
manner  of  installing  all  thermostats  now  on  the  market.    We  can 


101 — Balanced    Check    Damper. 


say,  however,  that  all  are  substantially  alike  in  principle  and  are 
easily  attached  when  this  principle  is  clearly  understood. 


Automatic   Draft  Regulators 

Before  leaving  the  subject  of  temperature  regulators  we  desire 
to  call  attention  to  another  type  of  device  for  handling  the  drafts 
of  the  furnace.  We  refer  to  a  device  for  putting  the  drafts  on 
the  heater  at  some  pre-determined  hour  of  the  morning. 


i6o 


TEMPERATURE  REGULATION 


Fig.  102  illustrates  one  type  of  such  apparatus  and  Fig.  103 
another  type.  These  devices  are  known  as  draft  regulators, 
although,  strictly  speaking,  they  do  not  "regulate"  the  draft. 


Fig.  1 02 — "Mono"  Type  of  Regulator. 


The  office  of  this  type  of  regulator  is  to  automatically  close  the 
check  damper  and  open  the  draft  door  of  a  heater  in  the  morn- 


TO  DAMPCRS 


Fig.   103— "Peerless"  Type  of  Regulator. 

ing,  thus  allowing  the  fire  to  burn  and  the  rooms  to  become  warm 
that  the  family  may  rise  and  dress  comfortably. 


AND  FUEL  SAVING 


161 


Operation  and  Installation 

An  ordinary  type  of  alarm  clock  is  the  medium  by'  which  this 
type  of  regulator  is  controlled. 

Assuming  that  it  requires  about  an  hour  to  heat  the  house 
comfortably  and  that  the  hour  of  arising  is  seven  o'clock,  the 
heater  is  coaled  in  the  evening  before  retiring  and  the  dampers 


Fig.  104 — Controlling  Drafts  from  Living  Room. 

are  then  closed.  The  alarm  clock  is  then  wound  and  set  at  six 
o'clock.  There  is  no  alarm  on  the  clock,  but  in  its  stead  the 
mechanism  of  the  clock  trips  a  little  lever  which  allows  a  weight 
to  fall  a  distance  of  twelve  to  fifteen  inches.  Chains  are  attached 
to  this  weight,  which  connect  with  the  drafts  of  the  heater,  and 
when  the  weight  falls  these  chains  open  the  draft  door  and 
close  the  check  damper. 

This  has  been  called  an  invention  for  a  lazy  man.  We  think, 
however,  that  the  method  of  running  the  apparatus  with  drafts 
closed  at  night  and  opened  automatically  in  the  morning  will 
appeal  to  any  person  who  realizes  the  health  fulness  of  sleeping 
in  a  cool  room  and  how  comfortable  it  is  to  rise  and  dress  in  a 
warm  room.  Aside  from  these  features,  the  use  of  such  a  device 
will  cause  a  considerable  saving  in  fuel,, 


1 62  TEMPERATURE  REGULATION 


Chain  Control  of  Drafts 

A  simple  method  of  controlling  the  drafts  of  the  furnace  from 
one  of  the  living  rooms  on  the  first  floor  should  also  be  provided 
as  an  accessory  to  the  furnace. 

A  rod  of  light  weight  iron  may  be  hung  from  an  arm  located 
above  the  furnace  and  the  draft  doors  of  the  heater  connected 
to  this  rod  by  means  of  chains.  From  one  end  of  the  rod,  a 
chain,  passing  over  pulleys,  is  connected  to  a  plate  located  against 
the  base-board,  in  a  room  above  the  furnace,  by  a  hook  on  the 
end  of  the  chain,  and  an  eyebolt  on  the  plate.  Hooking  the 
chain  to  the  upper  eye  opens  the  draft  doors  of  the  furnace  and 
lowering  it  to  the  bottom  eye  closes  the  drafts.  Fig,  104  shows 
the  method  of  making  this  attachment.  The  ornamental  plate 
may  be  of  cast  iron,  bearing  the  name  of  the  heating  contractor 
and  is  a  standing  advertisement  for  him. 

Some  furnace  manufacturers  furnish  similar  plates  and  chains, 
but  we  find  that  these  are  seldom  made  use  of  by  the  furnace 
men. 

It  is  the  consideration  given  by  the  live  furnace  contractor  to 
devices  of  the  above  description  that  makes  for  success,  and 
marks  his  work  as  above  the  average  in  the  consideration  of  the 
house  owner  and  possible  customer. 


CHAPTER  XVI 

FUEL:    ITS    CHEMICAL    COMPONENTS    AND    COM- 
BUSTION 

To  the  great  mass  of  people  coal  is  known  simply  as  coal — 
anthracite  or  bituminous — hard  or  soft.  Most  users  of  coal  as 
a  fuel  for  heating  or  cooking  accept  of  conditions  as  they  are 
found  locally,  and  burn  the  fuel  found — or  more  properly  sold — 
in  the  local  market,  without  regard  to  its  value  as  a  heat  produc- 
ing commodity.  To  such  people  a  ton  of  coal  is  simply  a  ton  of 
coal — nothing  more. 

We  wish  to  discuss  this  question,  and  try  to  determine  and 
make  clear  what  preparation  is  necessary  to  properly  burn  cer- 
tain kinds  of  fuel  in  the  hot  air  furnace. 

The  principal  factor  of  value  in  coal  for  use  as  a  fuel  for 
heating  is  the  amount  of  fixed  carbon  it  contains — carbon  being 
the  principal  heat  producing  matter  in  all  fuels. 

It  is  said  by  those  wizards  of  the  present  age,  the  chemists, 
that  all  coals  contain  two  exactly  opposite  matters,  namely :  com- 
bustible or  heat  producing  matter,  and  non-combustible  or  non- 
heat  producing  matter.  They  sub-divide  these  matters  ai 
follows : 

Combustible  Matter — 

Volatile  Matter  (Gas) 
Fixed  Carbon  (Coke) 

Non-combustible  Matter : 
Moisture  (Water) 
Ash  (Refuse) 

In  addition  to  the  above,  there  is  present  a  rank  impurity 
called  sulphur.  This  is  sub-divided  as  follows: 

(a)  Volatile   sulphur,   which    disappears    in   the   smoke   and 
products  of  perfect  combustion ;  and 

(b)  Iron  pyrites  or  sulphuret  of  iron,  which  causes  the  coal 
to  clinker  and  run  on  the  grate  bars. 

To  deviate  a  little  from  the  subject,  we  desire  to  say  that  many 
of  our  readers  live  in  localities  where  a  fuel  is  burned  which  is 
mined  locally,  and  where  these  last  conditions  are  particularly 


164  COMBUSTION  OF  FUEL 

noticeable.  For  instance,  in  certain  sections  of  Illinois  a  coal 
is  mined  and  used  which  is  fed  to  the  furnace  or  stove  in  large 
chunks.  A  short  time  after  the  coal  has  been  supplied  to  the 
furnace  or  stove,  and  while  the  large  chunks  are  still  intact,  a 
slight  rap  with  a  poker  or  slice-bar  will  cause  it  to  separate  or 
break  into  small  pieces,  and  after  burning  for  a  period  it  be- 
comes semi-liquid  and  can  be  stirred  on  the  grate  like  a  mass  of 
molten  lava. 

A  like  condition  is  found  in  certain  varieties  of  coal  mined  in 
West  Virginia,  Ohio,  and  some  other  localities. 

Another  condition,  due  to  the  presence  of  iron  pyrites  in  some 
varieties  of  coal,  is  the  fusing  or  attaching  of  particles  of  ash 
and  partially  burned  coal  into  a  mass  of  clinker.  This  is  par- 
ticularly noticeable  in  furnaces  or  heaters  not  properly  con- 
structed to  admit  of  perfect  combustion  of  the  fuel. 

Returning  to  the  consideration  of  the  chemical  analysis  of  coal, 
as  given  above,  we  may  say  that  all  coal  contains  gas,  coke,  water, 
sulphur,  and  refuse,  and  for  all  purposes  the  coal  which  con- 
tains the  most  fixed  carbon  (coke),  together  with  the  greatest 
percentage  of  volatile  matter  (gas),  is  the  most  valuable  for  use 
as  a  fuel. 

We  say  "for  all  purposes,"  as  the  great  mass  of  users  of  coal 
as  a  fuel  fail  to  consider  that  certain  varieties  of  coal  are  best 
adapted  for  certain  kinds  of  work. 

The  proportions  of  volatile  matter  and  fixed  carbon,  as  found 
in  some  varieties  of  coal,  seem  to  have  been  blended  for  certain 
uses. 

Some  anthracite  coal  is  very  rich  in  carbon,  containing  pos- 
sibly 85  to  90  per  cent.,  and  low  in  the  percentage  of  volatile 
matter  (gas)  ;  does  not  clinker,  and  when  once  thoroughly  ig- 
nited will  burn  for  a  long  period.  These  features  make  it  par- 
ticularly adaptable  for  use  in  stoves,  furnaces,  and  other  heat- 
ing apparatus. 

Some  cannel  coal  is  so  full  of  gas  and  so  low  in  carbon,  con- 
taining as  high  as  60  per  cent,  of  volatile  matter,  that  it  can  be 
lighted  with  a  match.  While  speaking  of  cannel  coal,  we  may 
mention  the  fact  that  the  word  "cannel"  is  a  corruption  of  the 
word  "candle."  In  Lancashire,  England,  the  name  "candle"  was 
first  given  to  this  variety  of  coal  owing  to  the  fact  of  its  being 
easily  lighted,  and  that  when  kindled  it  burns  with  a  highly 
luminous  yellow  flame,  much  like  a  lamp,  without  melting.  The 
Lancashire  pronunciation  of  the  word  candle  is  "cannel,"  and 
in  England  and  Soctland  the  farmers  used  this  coal  for  candles 
— hence  its  name. 


COMBUSTION  OF  FUEL  165 

Experience  has  taught  us  that  it  is  unprofitable  to  burn  an- 
thracite coal  under  boilers  used  for  power,  and  that  where  the 
generation  of  steam  is  the  main  object  sought,  we  should  use  a 
coal  with  a  good  percentage  of  fixed  carbon  and  a  fairly  large 
Dercentage  of  volatile  matter,  or  gas,  as  such  coal  contains  a 
larger  amount  of  heat  units  than  any  other  combination  or  blend- 
ing of  these  elements.  On  the  contrary,  it  has  been  proven 
conclusively  that  anthracite  is  far  superior  to  any  bituminous 
coal  for  use  in  a  stove  or  heating  apparatus,  owing  to  the  larger 
percentage  of  fixed  carbon  and  the  smaller  percentage  of  vola- 
tile matter  contained  in  k. 

This  may  seem  strange  to  those  who  have  not  studied  the  sub- 
ject, and  yet  it  is  easily  accounted  for.  When  under  a 
factory  or  other  power  boiler,  the  best  and  most  economical 
results  are  obtained  from  burning  the  largest  possible  number 
of  pounds  of  coal  per  hour  on  each  square  foot  of  grate,  and  a 
blower  is  frequently  used  to  supply  large  quantities  of  air,  and 
thus  stimulate  combustion  in  order  to  accomplish  this  result, 
when  the  latter  conditions  prevail,  we  demand  a  slow  rate  of 
combustion  and  try  to  burn  as  little  coal  per  square  foot  of  grate 
per  hour  as  possible  to  maintain  the  desired  temperature. 

Tests  have  shown  that  certain  manufacturing  needs  demand 
a  certain  grade  of  coal — that  for  each  different  kind  of  coal  there 
is  a  specific  manufacturing  or  commercial  need. 

We  have  compared  anthracite  and  cannel  coal  as  being  the 
extremes  in  the  percentage  of  fixed  carbon  and  volatile  matter 
contained.  There  are  several  kinds  of  coal  which  may  be  classi- 
fied between  these  two  varieties.  These  may  be  classified  as 
follows,  the  percentages  given  being  a  fair  average: 

Kinds.  Volatile  Matter.  Fixed  Carbon. 

Anthracite    7  per  cent.  85  to  90  per  cent. 

Semi-Bituminous    18  per  cent.  75  to  80  per  cent. 

Bituminous    24  per  cent.  70  to  72  per  cent. 

Semi-Gas    30  per  cent.  60  to  65  per  cent. 

Cooking    33  per  cent.  58  to  60  per  cent. 

Gas    37  per  cent.  55  to  58  per  cent. 

Our  discussion  of  fuels  would  not  be  completed  without  say- 
ing a  few  words  about  coke. 

Coke  is  a  brittle,  porous  solid.  It  is  a  dark  gray  in  color,  and 
is  artificially  manufactured  by  a  process  called  "coking,"  which 
consists  in  expelling  all  of  the  volatile  matter  (gas)  fromi 
bituminous  coal,  this  process  being  usually  carried  on  in  ovens 
made  of  firebrick.  Charcoal  is  introduced  into  the  top  of  the 
oven  and,  being  lighted,  a  little  air  is  admitted  through  openings 


1 66  COMBUSTION  OF  FUEL 

in  the  front.  When  the  coal  in  the  oven  ceases  to  emit  smoking1 
vapors  the  supply  of  air  is  cut  off,  and  the  oven  allowed  to  cool 
for  a  day  or  two.  A  door  in  the  front  of  the  oven  is  opened, 
and  the  hot  coke  is  then  raked  out.  Water  is  thrown  upon  it 
to  stop  further  combustion.  A  net  ton  of  coal  (2,000  pounds) 
will  make  from  1,000  to  1,600  pounds  of  coke,  depending  upon 
the  character  of  the  coal.  Coke  does  not  smoke  when  burning, 
and  gives  off  a  large  amount  of  heat. 

As  we  are  considering  the  relative  value  of  different  varieties 
of  coal  as  a  fuel  for  heating  apparatus,  rather  than  the  value 
of  the  coal  as  a  commodity,  this  latter  subject  has  no  place  in 
our  discussion,  and  yet  there  is  one  thought  to  which  we  wish 
to  call  attention. 

As  stated,  from  1,000  to  1,600  pounds  of  coke  are  available 
for  each  2,000  pounds  of  bituminous  coal  thus  converted. 

By  inquiry  at  any  gas-making  establishment — gas-works  we 
call  it — where  coal-gas  is  produced,  our  readers  will  find  that 
about  10,000  cubic  feet  of  gas  are  obtained  from  2,000  pounds 
of  bituminous  or  coal-gas.  When  we  consider  the  value  in  heat 
units,  or  as  a  heat  producer,  of  1,000  to  1,600  pounds  of  coke 
plus  10,000  cubic  feet  of  coal-gas,  we  may  learn  something  of 
the  real  value  of  one  tone  of  bituminous  coal. 

To  burn  coal,  coke,  gas,  or  any  other  fuel  it  is  necessary  to 
mix*  oxygen  with  it.  Therefore  it  is  necessary  to  admit  a  suffi- 
cient amount  of  atmosphere  to  supply  this  oxygen.  The  car- 
buretted  hydrogen  (gas)  and  the  carbon  of  the  fuel  must  each 
be  supplied  with  the  necessary  amount  of  oxygen,  and  be  kept 
at  the  required  temperature  to  produce  the  chemical  action  neces- 
sary for  perfect  combustion. 

Some  idea  of  the  volume  of  air  necessary  may  be  obtained 
by  considering  the  statement  that  for  the  complete  combustion 
of  the  volatile  constituents  of  a  ton  of  coal  100,000  cubic  feet 
of  air  is  required.  This  is  figured  from  certain  definite  data, 
which  show  that  we  are  obliged  to  make  use  of  five  cubic  feet 
of  air  to  supply  one  cubic  foot  of  oxygen,  and  to  obtain  20,000 
cubic  feet  of  oxygen,  the  amount  necessary  for  the  complete 
combustion  of  a  ton  of  coal,  requires  five  times  twenty  or  100,- 
ooo  cubic  feet  of  atmosphere  air. 

The  admission  of  too  little  air  will  allow  much  of  the  gas  to 
pass  off  unburned,  and  the  admission  of  too  much  air  will  cool 
the  fire  or  combustion  chamber  of  the  furnace  and  reduce  the 
temperature,  thus  preventing  perfect  combustion. 

From  the  above  statement,  it  is  evident  that  in  order  to  obtain 
the  best  resuts  form  the  fuel  used,  we  must  build  our  furnace 
in  such  form  that  the  gases  or  volatile  matter  in  the  fuel  can  be 


COMBUSTION  OF  FUEL  167 

properly  ignited  and  burned,  and  from  this,  also,  we  may  es- 
tablish the  fact  that  a  furnace  which  will  give  good  results  with 
Pennsylvania  anthracite  as  a  fuel  will  prove  a  flat  failure  with 
Illinois  bituminous  coal. 

It  is  entirely  a  matter  of  proper  furnace  construction,  taking 
into  consideration  the  character  of  the  fuel  to  be  used  and  the 
locality  where  the  furnace  is  to  be  installed,  and  in  our  considera- 
tion of  the  construction  of  furnaces  as  best  adapted  for  burning 
certain  grades  of  fuel,  we  shall  neither  discuss  the  production 
of  the  apparatus  from  the  standpoint  of  the  manufacturer,  nor 
cover  the  merits  of  any  particular  type  of  furnace. 

The  several  simple  sketches,  Figs.  105,  106  and  107  illustrate 
the  three  general  methods  employed  in  furnace  construction  to 
provide  a  means  for  the  passing  off  of  the  smoke  and  products 
of  combustion,  and  there  are  many  forms  and  variations  of  each 
idea. 

Fig.  105  represents  the  direct  method  and  involves  a  direct 
passage  into  the  smoke  flue  of  the  products  of  combustion.  By 
it  all  air  moving  through  the  furnace  is  warmed  by  the  direct 
radiation  of  the  heat  from  the  fuel  consumed.  All  furnaces  of 
this  type  are  wasteful  of  fuel,  and  yet  there  are  certain  grades 
of  coal,  full  of  iron  pyrites,  sulphur  and  other  impurities,  which 
can  be  successfully  burned  only  in -a  furnace  of  this  kind.  In 
any  other  type  the  tarry  smoke  will  encrust  the  heating  surfaces 
of  the  furnace,  rendering  them  practically  useless,  or  what  is 
still  worse,  will  completely  clog  the  flue  passages  through  it. 

Fig.  106  illustrates  the  semi-indirect  plan  of  furnace  construc- 
tion, and  it  is  safe  to  say  that  ninety  per  cent,  of  the  manufac- 
turers adopt  this  method  or  some  form  of  it  in  their  type  of 
warm  air  apparatus.  It  is  well  known  that  in  order  to  success- 
fully burn  a  large  percentage  of  the  coal  gas  or  carburetted 
hydrogen,  it  must  be  retained  within  the  fire  chamber  until  suf- 
ficient oxygen  can  mix  with  it  to  produce  combustion.  This 
means  that  for  every  cubic  foot  of  coal  gas  extracted  from  the 
fuel,  two  cubic  feet  of  oxygen  must  be  applied  or  enter  into 
union  with  it  to  cause  perfect  combustion,  and,  as  stated  in  the 
precious  chapter,  it  will  be  remembered  that  in  five  cubic  feet 
of  reasonably  pure  air  there  is  present  but  one  cubic  foot  of 
oxygen. 

Hence,  to  properly  consume  a  cubic  foot  of  coal  gas  requires 
the  admission  of  ten  cubic  feet  of  air  into  the  fire  chamber  of 
the  furnace. 

Now,  in  order  to  do  the  work  advantageously  this  supply 
must  be  admitted  at  a  certain  time,  a  certain  place,  and  in  a 
certain  manner,  and  it  is  by  reason  of  these  essential  require- 
ments that  the  goods  of  so  many  manufacturers  of  furnaces 


1 68 


COMBUSTION  OF  FUEL 


have  "fallen  down"  on  efficiency  tests.  As  stated  before,  too 
little  air  will  not  prevent  the  gas  from  passing  off  unburned, 
while  an  overabundant  supply  will  cool  the  fire  chamber  too 
much  and  retard  combustion. 

In  the  effort  to  retain  the  gas  within  the  furnace  until  it  shall 
be  consumed,  the  manufacturers  use  some  form  of  the  indirect 
method  illustrated  by  Fig.  106,  although  this  effort  is  exerted 
in  vain  unless  other  matters  are  also  provided  for  at  the  same 


Fig.   105 — Construction 
for   Indirect  Draft. 


J 


COMBUS 


Tl'ON     CHAMBER 


GHATE 

ASH  PIT 


i 


Fig.   106 — Construction 
for  Direct  Draft. 


time.  An  active  fire  will  produce  a  cubic  foot  of  coal  gas  very 
quickly.  Suppose  the  rate  of  combustion  is  four  pounds  per 
square  foot  of  grate  per  hour,  and  the  size  of  grate  three  square 
feet.  The  hourly  consumption  of  coal  in  such  a  furnace  would 
be  twelve  pounds.  If  we  consider  bituminous  gas  coal  as  a 
fuel  (10,000  cu.  ft.  gas  to  a  ton  of  2,000  Ibs.),  the  coal  burned 
will  produce  about  sixty  cubic  feet  of  gas  per  hour,  each  pound 
of  fuel  burned  giving  off  five  cubic  feet  of  gas,  and  requiring 
f.'fty  cubic  feet  of  air  to  consume  it. 

Now,  we  have  said  that  the  air  must  be  admitted  at  a  cer- 
tain place,  time  and  manner.  The  place  should  be  at  a  point  just 
above  the  normal  level  of  the  fire  in  order  that  the  air  may 
mingle  with  the  gases  arising  from  the  fuel.  The  gas  ring  ap- 
pliance usually  included,  and  shown  on  Figs.  105  and  107,  is 
made  of  cast  iron.  A  fire-pot  may  be  provided  with  firebrick 
lining  so  set,  or  held  in  place,  as  to  provide  an  air  space  between 


COMBUSTION  OF  FUEL 


169 


the  brick  and  the  outer  iron  cylinder,  the  air  passing  upward  from 
the  base  and  into  the  fire  chamber  through  small  holes  in  the 
lining,  as  illustrated  by  Fig.  108. 

The  proper  time  for  the  admission  of  this  air  is  when  the  gas 
is  burning  off  from  a  fresh  charge  of  cool,  because  probably 
eighty-five  per  cent,  of  all  gas  in  the  coal  burned  is  given  off 
during  the  hour  following  the  time  that  the  additional  fuel  is 
added,  provided  the  draught  is  on  the  furnace. 

The  manner  in  which  this  air  should  be  admitted  is  in  small 
sprays  above  the  fire,  and  its  temperature  should  be  practically 
the  same  as  that  of  the  gas.  When  the  supply  is  taken  in  through 
a  gas  ring,  or  through  the  top  of  the  firebrick,  as  shown  by  Fig. 
108,  its  velocity  is  about  four  times  as  great  as  that  of  the  air 
passing  in  the  lower  draught  door  and  upward,  and  should  this 
volume  of  air  move  upward  through  the  coal,  the  rate  of  com- 
bustion would  be  so  rapid  that  a  large  share  of  the  gas  would 
pass  out  of  the  smoke  pipe  unconsumed. 


Fig.  107 — Construction  for  Semi-Indirect  Draft. 

The  principle  shown  by  Fig.  107  is  used  in  the  construction 
of  furnaces  for  both  hard  and  soft  coal. 

The  indirect  method  illustrated  by  Fig.  106  is  adapted  more 
particularly  to  building  furnaces  for  hard  or  anthracite  coal, 
and  a  wonderful  variety  of  forms  and  ideas  is  followed  by 
manufacturers  in  carrying  out  the  principle  shown.  The  per- 
centage of  volatile  matter  in  anthracite  coal  is  so  small  that  little 
or  no  attention  is  given  to  burning  the  gases.  Combustion  is 
not  so  rapid  as  with  soft  coal,  and  any  air  admitted  above  the 
fire  has  a  tendency  to  chill  it.  The  temperature  in  the  fire 


170 


COMBUSTION  OF  FUEL 


chamber  should  be  high,  in  order  to  provide  for  complete  com- 
bustion, and  the  firepot  for  burning  anthracite  should  be  almost 
straight  up  and  down  or  possibly  a  little  larger  in  diameter  at 
the  grate  line  than  at  the  top;  also,  its  surface  should  be  cor- 
rugated. 


6/tATS 


Fig.  1 08 — Fire  Pan  with  Air  Holes  in  Lining. 

By  considering  the  foregoing  facts  regarding  the  furnace  con- 
struction we  shall  accept  the  following  definite  conclusions : 

(a)  That  furnaces  should  be  selected  according  to  the  character 
of  the  fuel  to  be  used. 

(b)  That  the  gas  or  volatile  matter  in  all  coal  other  than 
anthracite  is  of  greater  value  than  the  carbon  (coke)   for  heat- 
ing purposes. 

(c)  That,  in  order  to  utilize  the  greatest  number  of  heat  units 
in  bituminous  and  semi-bituminous  coal,  it  is  necessary  to  make 
proper  provision  for  burning  the  gas  first  and.  the  coke  last,  or, 
stated  in  another  form,  to  appropriate  the  full  value  of  the  gas 
for  heating,  retaining  the  coke  for  rekindling  requirements. 

(d)  That  the  loading  of  a  fire  with  fresh  fuel  obstructs  the 
volume  and  velocity  of  the  air  admitted  through  the  grate,  mak- 
ing it  necessary  to  inject  a  sufficient  quantity  of  air  above  the 
fire  to  properly  burn  the  gases. 

(e)  That    unless    this    deficiency    is   provided    for   all    com- 
bustible  gases,    such   as    hydrogen,    carburetted   hydrogen,    and 
carbonic  oxide,  will  escape  up  the  chimney  flue,  the  smoke  plainly 
indicating  the  loss  sustained. 

(f)  That   in   introducing  heated,   and   consequently   rarefied 
air,  into  the  combustion  chamber  of  the  furnace  in  small  jets, 
through  a  gas  ring,  or  perforated  firebrick,  a  sufficient  supply 
of  oxygen  can  be  admitted  without  cooling  the  gases  and  perfect 
combustion  obtained  from  the  thorough  mixture  of  the  oxygen 
with  the  gases. 

As  an  all-important  part  of  a  furnace,  the  grate  should  be 
of  such  shape  and  character  that  the  ashes  may  be  removed 
from  the  firepot  without  stirring  up  the  body  of  unconsumed  coal 


COMBUSTION  OF  FUEL  171 

lying  above  them.  The  nature  or  size  of  the  opening  between 
the  bars  has  little  to  do  with  a  greater  or  lesser  consumption 
of  coal.  The  grate  is  simply  a  cradle  which  holds  the  fuel  and 
the  amount  burned  is  governed  by  the  quantity  of  air  passed 
through  the  grate. 

It  is  possible  to  consume  the  fuel  without  benefit,  under  which 
circumstances,  of  course,  the  combustion  will  not  be  perfect, 
and  while  the  fire  appears  dead  or  passive,  yet  more  fuel  is 
burned  than  would  be  the  case  if  the  combustion  were  positive 
and  the  fire  active.  The  remedy  for  such  a  condition  is  found 
in  the  admission  of  air — oxygen — in  the  right  place  and  manner 
and  in  sufficient  quantity. 

Coal :  The  Universal  Fuel 

A  brief  narration  of  the  facts  regarding  the  discovery  and 
development  of  the  coal  deposits  of  the  world,  and  particularly 
those  of  the  United  States,  will  prove  interesting  to  all  persons 
connected  with  the  manufacture  and  installation  of  heating  ap- 
paratus. 

Coal  is  the  universal  fuel,  and  without  its  use  it  is  doubtful 
if  the  nations  of  the  world  could  have  made  such  progress  in 
manufacture  and  civilization  as  history  has  recorded. 

We  are  accustomed  to  think  of  coal  as  being  principally  a 
product  of  the  United  States;  and  while  it  is  true  that  we  now 
lead  all  other  nations  in  the  tonnage  of  coal  mined,  this  stand- 
ing has  been  reached  only  in  recent  years. 

We  know  that  more  than  2,000  years  ago  coal  was  an  article 
of  commerce  in  certain  parts  of  the  Chinese  empire  and  had 
been  known  for  years  prior  to  that  period.  It  is  also  recorded 
that  coal  was  shipped  into  London  in  the  year  1240. 

Virginia  bituminous  coal  was  mined  as  early  as  the  year  1750 
and  in  1768  anthracite  coal  was  mined  in  the  Wyoming  Valley, 
Pennsylvania,  near  what  is  now  the  city  of  Wilkes-Barre,  and 
in  the  years  1770-76-91  coal  was  mined  in  other  sections  of 
Pennsylvania. 

It  is  related  that  in  the  year  1812  Colonel  Geo.  Shoemaker 
of  Pottsville,  loaded  nine  wagons  of  coal  from  the  Schuylkill 
region  and  hauled  it  to  Philadelphia  where,  with  difficulty,  he 
sold  two  loads  and  gave  the  other  seven  loads  away.  He  was 
regarded  as  an  imposter  and  with  some  trouble  avoided  arrest 
by  getting  out  of  the  city. 

White  &  Hazard,  owners  of  a  wire-works  at  the  Falls  of 
Schuylkill,  bought  one  of  the  loads  and  a  whole  night  was  spent 
by  their  workmen  in  efforts  to  make  the  coal  burn.  They  gave 


172  COMBUSTION  OF  FUEL 

up  and  quit  their  work,  leaving  the  door  of  the  furnace  closed 
and  one  of  the  workmen  returning  for  some  forgotten  clothing 
found  everything  red-hot. 

This  effort  to  burn  coal  is  exceedingly  interesting  when  we 
consider  that  100  years  later  (1912)  the  United  States  produced 
about  one-third  of  all  the  world's  supply,  leading  England  by 
millions  of  tons  and  Germany,  her  next  nearest  rival,  by  a 
tonnage  three  times  greater. 

As  a  matter  of  fact  this  great  development  has  taken  place 
\vithin  the  last  forty  years  as  the  coal  production  in  the  United 
States  in  1866  was  less  than  15,000,000  tons. 


CHAPTER  XVII 

CEMENT  CONSTRUCTION  FOR  FURNACE  MEN 

When  engaged  in  the  business  of  installing  warm  air  heating 
appartus  the  sheet  metal  worker  should  be  independent  of  other 
contractors.  In  making  this  statement  we  mean  to  say  that  in 
order  to  reap  the  full  benefits  accruing  from  a  contract  the  fur- 
nace man  should  install  his  work  without  the  services  of  a  car- 
penter or  mason.  He  should  be  sufficiently  familiar  with  the  use 
of  carpenters'  tools  to  do  his  own  cutting  and  framing,  and  he 
should  also  be  able  to  construct  foundations,  cold  air  pits,  and 
ducts,  and  to  instruct  his  men  how  to  build  them  without  the 
assistance  of  a  mason  or  cement  contractor. 

The  present  period  is  sometimes  called  the  age  of  cement,  by 
reason  of  the  fact  that  cement  is  now  so  generally  used  in  build- 
ing construction  of  all  kinds,  and  we  desire  to  call  attention 
to  the  proper  method  of  mixing  and  using  cement. 

A  volume  would  be  required  to  treat  this  subject  in  a  thorough 
manner.  We  shall,  however,  in  this  brief  article  be  able  to  show 
how  to  use  cement  successfully,  and  also  to  point  out  the  rea- 
son why  so  many  furnace  men  fail  to  obtain  proper  results  when 
attempting  to  build  pits  and  ducts  of  concrete. 

Concrete  Mixtures 

All  cement  mixtures  are  not  alike  in  strength  or  consistency. 
A  certain  mixture  that  might  be  best  for  one  class  of  work  would 
not  do  for  work  of  another  class.  Mixtures  of  concrete  of 
greatly  different  strength  and  costs  can  be  made  of  the  same 
materials,  simply  by  combining  them  in  different  quantities. 

In  our  discussion  of  concrete  mixtures  we  shall  make  use  of 
two  terms  which  should  be  explained.  These  terms  are  aggre- 
gates and  voids.  Aggregates  are  the  solid  and  coarse  ingredients 
which  are  bound  together  by  the  cement  in  making  a  mass  of 
concrete.  Materials  such  as  sand,  gravel,  trap  rock  or  crushed 
stone,  cinders,  etc.,  are  known  to  cement  workers  as  aggregates. 

Voids  are  the  air  spaces  between  the  particles  of  aggregates 
which  must  be  filled  or  removed  from  all  cement  work  in  order 


174  CEMENT  CONSTRUCTION 

to  make  the  work  substantial.  For  example,  the  voids  in  sand 
are  rilled  with  cement  and  this  mixture  is  used  to  fill  the  voids 
in  gravel  or  broken  rock. 

The  ability  to  judge  by  sight  or  determine  by  test  the  propor- 
tions of  materials  for  a  cement  mixture  is  gained  only  through 
long  experience,  and  it  is  essential  that  the  mixture  be  right  for 
the  work  in  hand.  A  certain  mixture  for  a  foundation  pit  or 
duct  in  a  cellar  which  is  always  dry  would  not  do  for  building 
a  foundation  pit  or  duct,  which  of  necessity  must  be  watertight 
on  account  of  a  cellar  being  wet  at  certain  periods  of  the  year, 
nor  would  a  mixture  suitable  for  building  a  sidewalk  be  right 
for  use  in  constructing  a  cistern. 

Concrete  mixtures  are  classified  in  two  different  ways.  First 
as  to  richness,  meaning  the  quantity  of  cement  used,  and  sec- 
ondly as  to  consistency  or  wetness. 

When  so  classified  a  cement  mixture  is  known  as  rich,  medium, 
ordinary  and  lean.  A  i  :2  14  mixture  would  be  called  a  rich 
mixture.  The  formula  I  12  14  indicates  one  barrel  of  cement 
(four  bags  to  the  barrel)  to  two  barrels  of  sand,  and  four  barrels 
of  gravel  or  broken  stone  or  other  coarse  aggregates. 

A  I  12.5  15  mixture  is  one  barrel  of  cement,  two  and  one-half 
barrels  of  sand  and  five  barrels  of  broken  stone  or  loose  gravel, 
and  this  combination  of  materials  would  be  classified  as  a  ''medi- 
um" mixture. 

A  I  13  :6  mixture  measured  in  like  manner  is  known  as  an 
"ordinary"  mixture,  and  a  I  14  :8  combination  of  cement,  sand 
and  gravel  as  a  "lean"  mixture. 

In  consistency  the  mixture  may  be  "very  wet,"  "medium 
wet"  or  "dry,"  the  amount  of  moisture  necessary  depending 
upon  the  work  for  which  it  is  intended. 

For  use  in  building  foundations  and  ducts  for  furnace  work 
a  "medium"  or  "ordinary"  mixture  "medium  wet"  is  desirable, 
provided  the  pit  or  duct  is  not  to  be  waterproof.  If  the  pit 
or  duct  must  be  waterproof  on  account  of  a  wet  basement,  or 
trouble  at  certain  periods  from  surface  water,  the  mixture  should 
be  a  i  :2  14  (rich)  or  a  I  12.5  15  (medium),  and  in  consistency, 
medium  to  very  wet. 

Mixing  Concrete 

There  are  several  methods  of  mixing  the  concrete.  The  sand 
and  cement  may  be  mixed  dry,  and  this  mixture  spread  layer 
upon  layer  upon  the  broken  stone,  gravel  or  aggregate  before 
the  water  is  added,  or  the  sand  and  cement  may  first  be^mixed 
with  water  into  a  mortar,  and  this  mortar  then  mixed  with  the 


CEMENT  CONSTRUCTION  175 

broken  stone  or  gravel,  after  which,  in  either  case,  it  should 
be  turned  with  a  shovel  until  a  thorough  mixture  of  the  ingredi- 
ents is  obtained,  or  until  all  particles  of  the  aggregates  are 
thoroughly  coated  with  the  cement  paste. 

There  are  several  kinds  of  cement  to  be  had,   the  best  for 
general  uc2  being  that  called  Portland. 


Fig.  109 — Trowel  for  Round  Corner  Work. 

Portland  cement  consists  principally  of  limestone  and  slag 
crushed  separately  and  dried  to  remove  all  moisture,  after  which 
each  ingredient  is  ground  extremely  fine.  After  being  combined 
in  a  certain  proportion  this  mixture  is  calcined  or  burned  to  a 
clinker.  This  clinker  is  then  cooled,  pulverized  fine,  and  mixed 
with  a  certain  quantity  of  gypsum,  when  it  is  ready  for  the 
storehouse,  where  it  is  kept  free  from  moisture  until  shipped 
or  supplied  for  use. 

The  Tools 

For  use  in  constructing  cement  ducts,  pits  and  other  work 
of  like  character,  but  very  few  tools  are  required  and  these  are 
inexpensive. 


Fig.  no— Trowel  for  Square  Corner  Work. 

Other  than  a  shovel,  hoe  and  ordinary  trowel  there  are  a  few 
tools  which  are  useful  and  convenient.  Fig.  109  illustrates  a 
smoothing  trowel  for  round  corner  work.  Fig.  no  a  smoothing 
trowel  for  square  corners.  Fig.  in  another  form  of  a  round 
corner  smoothing  trowel.  Fig.  112  shows  two  forms  of  a  tamper 
(a  tool  for  tamping  or  pounding  the  cement  mixture  to  remove 
the  voids),  which  may  be  made  from  any  heavy  iron  casting 
planed  smooth  on  the  lower  side  and  to  which  a  handle  mav 


176  CEMENT  CONSTRUCTION 

be  fitted.  These  tools  and  a  leveling  board  and  straight  edge 
are  all  that  the  furnace  man  will  require  for  the  class  of  cement 
work  he  will  be  called  upon  to  construct. 

Determining  Quantities 

In  connection  with  cement  work  the  following  data  will  prove 
useful  in  determining  quantities : 


Fig.  in — Trowel  for  Another  Form  of  Round  Corner. 


A  bag  of  natural  cement  weighs  94  pounds. 

A  bag  of  Portland  cement  weighs  94  pounds. 

A  barrel  of  natural  cement  equals  three  bags,  and  weighs 
about  282  pounds. 

A  barrel  of  Portland  cement  equals  four  bags,  and  weighs 
380  pounds. 

A  cubic  foot  of  crushed  or  broken  stone  weighs  about  90 
pounds. 


Fig.    112 — Tools  for  Tamping. 

One  bushel  of  cement  and  two  bushels  of  sand  mixed  to- 
gether to  form  a  cement  mortar  will  cover  3^2  square  yards 
one  inch  thick,  or  6^4.  yards  one-half  inch  thick.  (This  rule 
applies  for  a  smoothing  mixture  for  use  over  rough  concrete, 
brick  or  stone.) 


CEMENT  CONSTRUCTION  177 


Methods 

To  make  cement  mortar  (as  above)  adhere  to  old  or  finished 
cement  work,  the  surface  of  the  old  work  should  be  thoroughly 
soaked  with  water,  then  dust  on  a  little  neat  cement,  after  which 
apply  the  mortar  coat  before  the  dusted  cement  has  set. 

Another  method  equally  as  good  is  to  mix  a  thick  paint  of 
cement  and  water  and  brush  it  carefully  over  the  surface  of 
the  old  work  after  it  has  been  thoroughly  wet  with  water;  then 
apply  the  mortar  coat  quickly  before  the  paint  coat  has  set. 

It  is  not  a  difficult  matter  to  construct  good  cement  work  if 
care  is  exercised  in  the  selection  and  mixture  of  materials.  Do 
not  guess  at  quantities.  All  materials  used  should  be  carefully 
measured  or  weighed. 


CHAPTER  XVIII. 

CONSTRUCTION  AND  PATTERNS  OF  FURNACE 
FITTINGS 

Including   Bonnets,    Collars,   Elbows,    Cold  Air   Connections, 
Register  Boxes,  Transition  Boots,  Shoes,  Tees,  Offsets,  Etc. 

By  WILLIAM  NEUBECKER 

This  chapter  treats  the  various  methods  for  develop- 
ing and  constructing  the  many  styles  of  furnace  fittings,  as 
well  as  the  rule  to  be  followed  for  finding  the  true  angles 
of  elbows  from  given  dimensions.  In  designing  the  shape  of 
any  fitting  care  must  be  taken  not  to  reduce  the  given  area,  but 
to  have  the  same  area  throughout  the  entire  fitting  and  to  draw 
easy,  graceful,  frictionless  curves  to  facilitate  the  flow  of  air. 
While  there  are  many  styles  of  fittings  which  can  be  purchased, 
having  single  as  well  as  double  walls,  it  is  to  the  advantage  of 
the  furnace  man  to  understand  the  method  of  developing  the 
various  pattern  shapes,  a  knowledge  of  which  will  enable  him 
to  lay  out  any  required  shape  or  size. 


FURNACE  FITTINGS 


Conical  Bonnets  or  Hoods 


179 


The  first  subject  to  be  taken  up  will  be  development  of  the 
bonnet  or  hood.  A  good  type  of  a  bonnet  is  shown  in  Fig. 
113  with  a  deep  deflector.  The  method  of  developing  the  net 
patterns  for  the  bonnet  and  deflector  is  shown  in  Fig.  114  and 
is  accomplished  as  follows  :  Draw  any  vertical  line  as  A  B,  upon 
which  set  off  the  vertical  hight  of  the  bonnet  as  X  E,  bearing 
in  mind  to  make  this  3  inches  higher  than  the  largest  size  leader 
pipe  to  be  taken  from  it  (to  give  room  for  dovetailing  the  collar. 


Fig.    113 — Typical   Conical   Bonnet   with   Deflector   which   Determines 
the  Angle  of  Collar. 

Set  off  the  half  diameter  of  the  casing  as  X  C,  also  the  half 
diameter  of  the  top  of  the  bonnet  E  G.  Now  extend  C  G  until 
it  intersects  the  center  line  at  F.  Using  E  as  cented  with  radius 
equal  to  E  G,  draw  the  quarter  circle  G6,  which  divide  into 
equal  parts  as  shown.  This  quarter  circle  represents  the  plan 
on  the  line  E  G  and  would  be  the  quarter  pattern  for  a  flat  top 
casing  minus  the  edges.  Now  using  F  as  center  with  radii 


Quarter 
2* Pattern  of 
//  Deflector 


SECTION      B     HALF   ELEVATION 
Fig.  114 — Developing  Patterns  for  Bonnet  and  Deflector. 

equal  to  F  G  and  F  C,  draw  the  arcs  G  6'  and  C  C1.  On  the  arc 
G  6'  lay  off  the  girth  of  the  quarter  circle  as  shown  by  similar 
numbers  G  to  6'.  From  the  center  F  draw  a  line  through  6' 


i8o 


FURNACE  FITTINGS 


intersecting  the  outer  arc  at  C1.  Then  will  C  C1  6'  G  be  the 
quarter  pattern  for  the  bonnet,  to  which  edges  must  be  allowed 
for  riveting  and  seaming.  With  radius  equal  to  D.  G,  from  Dl 
as  center,  draw  the  arc  i"  6".  Set  off  on  the  arc  i"  6"  the  girth 
of  the  quarter  circle  as  shown,  and  draw  the  radial  lines  i"  D1 
and  6"  D1.  This  gives  the  quarter  pattern  minus  the  laps  fcr 
the  deflector. 


Fig.  1 16 — Collars  Joining  a  Straight  Bonnet. 


^-=s=^-     jf 

Fig.  115— Spacing 

the  Casing  Rings.  Fig.    117 — Collars  Joining  a   Flat   Top    Casing 

The  left  half  of  the  diagram  is  constructive,  showing  the 
seaming  of  the  deflector  to  the  bonnet  at  H,  and  the  seaming 
of  the  bonnet  to  the  casing  collar  at  J.  When  laying  out  the 
various  patterns  we  must  consider  the  width  of  the  iron  being 
used,  so  as  to  cut  without  having  much  waste.  The  casing 
collar  or  rim  C  is  usually  made  about  3  inhces  wide  so  as  to  fit 
the  casing  ring.  Another  way  is  to  allow  about  an  inch  lap 
along  the  curve  C  C1  in  the  pattern  and  after  the  full  bonnet 
has  been  riveted  together,  crimp  the  bottom  edge  on  a  crimper 
until  it  fits  the  casing  ring  snugly.  The  deflected  part  of  the 
bonnet  is  usually  filled  with  sand,  but  sometimes  an  additional 
sand  ring  is  seamed  to  the  top  edge  at  H,  making  it  about  2 
inches  high,  placing  a  wire  edge  along  the  top.  The  above 
rule  applies  to  any  size  or  pitch  of  bonnet. 


FURNACE  FITTINGS  181 

Furnace  Casings 

Casings  should  be  double  as  indicated  in  Fig.  115  and  care 
must  be  taken  that  the  casing  rings  are  so  placed  that  stock 
widths  of  iron  can  be  used.  The  rings  A,  B  and  C  should  be 
so  placed  that  the  distances  between  will  allow  using  sheets 
either  24,  26,  28,  30  or  36  inches  wide  without  waste.  When  the 
casing  rings  are  not  correctly  placed,  it  necessitates  using  short 
pieces  cut  across  the  sheets,  thereby  using  time  and  labor  and 
wasting  material,  and  does  not  make  as  neat  an  appearance,  as 
when  the  sheets  are  rolled  up  lengthwise.  The  circumference 
of  the  casing  is  obtained  by  the  use  of  a  narrow  strip  of  me<r.\ 
passing  it  around  the  ring,  holding  it  snugly,  and  then  allowing 
edges  for  riveting  or  seaming. 

Various  Styles  of  Collars 

There  are  three  styles  of  collars  usually  employed,  viz.:  One 
joining  a  pitched  bonnet,  as  shown  in  Fig.  113,  another  joining  a 
straight  bonnet  as  shown  in  Fig.  116,  and  the  third  joining  a 
flat  top  casing  as  shown  in  Fig.  117.  In  developing  the  pattern 
for  a  collar  joining  a  pitched  bonnet,  as  shown  in  Fig.  113,  the 
pitch  of  the  collar  b  is  usually  made  the  same  as  the  pitch  of 
the  deflector  a,  although  this  is  not  always  done.  Some  me- 
chanics do  not  develop  the  collar  and  opening  in  the  bonnet  by 
the  geometrical  rule,  but  roll  up  a  piece  of  pipe  and  trim  it  to 
fit  the  bonnet  at  the  desired  angle  and  then  mark  off  the  open- 
ing on  the  bonnet  and  trim  with  the  circular  shears.  While 
good  results  may  be  obtained  in  this  manner,  it  is  better  to  de- 
velop the  patterns  accurately,  which  can  be  saved  for  future 
use  or  be  slightly  modified  for  different  construction. 

Patterns  for  Collar  on  Pitched  Bonnet 

The  method  of  developing  the  patterns  for  collars  on  pitched 
bonnets  is  shown  in  Fig.  118.  First  draw  the  center  line  X  B, 
upon  which  establish  the  hight  of  the  bonnet  as  C  D.  From  C 
and  D  at  right  angles  to  X  B  draw  the  lines  C  6  and  D  Y,  equal 
respectively  to  the  semi-diameters  of  the  casing  and  top.  Con- 
nect 6  with  Y,  extending  the  line  until  it  meets  the  center  line 
at  X.  Now  with  radius  equal  to  C  6,  from  any  point,  as  H, 
on  the  line  X  B,  as  center,  draw  the  quarter  plan,  6  V,  as  shown, 
and  from  II  in  plan  draw  H  J,  the  center  line  of  the  collar.  At 
the  proper  angle,  draw  the  elevation  of  the  collar,  indicated  by 
i'  E  F  5'  and  in  its  proper  position  to  the  right  as  shown,  draw 
the  profile  of  the  collar,  which  divide  into  equal  spaces  as  shown 
from  i  to  5.  With  its  center  at  m  describe  a  half  profile  of  the 
collar  as  shown  in  plan,  dividing  it  as  before,  being  careful  in 


1 82 


FURNACE  FITTINGS 


numbering  the  spaces  to  see  that  the  line  i  5  in  the  profile  of  the 
collar  in  elevation  is  perpendicular  to  the  lines  of  the  collar  and 
parallel  to  the  lines  of  the  collar  in  plan,  all  as  shown. 

Divide  part  of  the  quadrant  6  V  in  plan  in  equal  spaces  as 
shown  by  points  6,  7  and  8,  from  which  points  draw  radial  lines 
to  the  center  H.  From  the  points  6,  7  and  8  erect  vertical  lines 
cutting  the  base  line  of  the  cone  in  elevation  at  6,  7  and  8  of 
1'iat  view,  from  which  points  draw  radial  lines  to  the  apex  X. 


B 


Section  on  2 


Section  on  4-4 
Section  on  3-3  . 

Fig.  1 18— Method  of  Obtaining  Patterns  for  Collar  and  Opening  to  Be 
Cut  in   Pitched   Bonnet. 


Through  the  small  figures  2,  3  and  4  in  the  profile  of  collar  in 
elevation,  draw  lines  at  right  angles  to  X  6  or  E  F  cutting  the 
radial  lines  in  elevation.  Where  the  line  2  2  cuts  the  radial 
lines  drawn  from  6,  7  and  8,  at  a  b  and  c,  drop  vertical  lines  in 
the  plan,  until  they  intersect  similar  numbered  radial  lines  6,  7 
and  8  in  plan  also  shown  by  a  b  and  c.  A  line  traced  through 


FURNACE  FITTINGS  183 

these  points  will  represent  the  partial  section  on  the  line  2  2  in 
elevation.  In  a  similar  manner  where  the  planes  3  3  and  4  4  in 
elevation  cut  the  radial  lines  6,  7  and  8  at  d,  e  and  /  and  at  g,  h 
and  the  base  line  at  *,  drop  vertical  lines  intersecting  similar  num- 
bered lines  in  plan  at  d,  e  and  /,_  also  at  g,  h  and  i.  The  curved 
lines  d  e  f  and  g  h  i  represent  the  sections  in  plan  on  3  3  and 
4  4  in  elevation.  Through  the  points  2,  3  and  4  in  the  half 
profile  in  plan,  draw  horizontal  lines  intersecting  the  various 
section  lines  in  plan,  as  shown  at  2',  3'  and  4'.  From  these  inter- 
sections, vertical  lines  can  now  be  erected  cutting  similar  num- 
bered section  lines  drawn  through  the  elevation  at  2,  3  and  4. 
A  line  traced  these  points  as  shown  by  i',  2,  3,  4  and  5'  will  be 
the  miter  line  between  the  collar  and  bonnet. 

The  pattern  for  the  collar  is  now  in  order  and  is  obtained  by 
extending  the  line  E  F  in  elevation  as  F  K,  upon  which  the  girth 
of  the  collar  profile  is  placed  as  shown  by  similar  numbers. 
Through  these  small  figures,  at  right  angles  to  F  K,  lines  are 
drawn  and  intersected  by  lines  drawn  parallel  to  F  K  from  cor- 
responding numbered  intersections  i',  2,  3,  4  and  5'.  Trace  a 
line  through  points  thus  obtained,  then  will  i  S  T  i  be  the  pat- 
tern for  the  collar,  to  which  laps  must  be  allowed  for  riveting 
and  seaming. 

The  pattern  for  the  opening  in  the  bonnet  is  obtained  as  fol- 
lows :  From  the  intersections  2,  3  and  4  in  the  miter  line  in 
elevation,  project  horizontal  lines  to  the  right,  intersecting  the 
outline  of  the  bonnet  at  2',  3'  and  4'.  From  X1  in  the  diagram 
on  the  right  as  center  with  radii  equal  X  Y,  X  i',  X  2,  etc.,  of 
the  elevation,  draw  short  arcs  as  shown  by  similar  numbers. 
From  H  in  the  plan,  draw  radial  lines  through  the  intersections 
2',  3'  and  4'  until  they  cut  the  base  line  as  shown  at  2",  3"  and  4". 
As  i'  and  5'  in  elevation  show  the  true  points  of  intersections 
on  the  bonnet  of  lines  from  points  bearing  those  numbers  in  the 
profile  of  the  collar,  these  points  will  be  shown  at  i"  5"  (point  6) 
on  the  base  line.  In  the  pattern  for  the  opening  in  bonnet,  es- 
tablish at  pleasure  any  line,  as  i"  X1  as  a  center  line,  and  from 
the  point  i"  set  off  either  way  on  the  arc  6"  6",  the  spaces  indi- 
cated by  the  numbered  points  4",  2"  and  3"  in  plan,  as  indicated 
by  similar  numbers  in  the  pattern.  From  these  points  draw 
radial  lines  to  X1,  intersecting  arcs  of  similar  numbers  previously 
drawn.  A  line  traced  through  points  thus  obtained  will  be  the 
desired  shape  of  the  opening,  which  is  shown  shaded. 

Should  the  collar  be  placed  to  one  side  of  the  center  of  the 
cone,  that  is  axially  oblique  as  shown  in  diagram  Z  at  the  top 
of  the  cut,  the  method  of  procedure  will  be  precisely  the  same 
as  that  just  described,  except  that  the  angle  of  projection  upon 
the  bonnet  will  be  different. 


1 84 


FURNACE  FITTINGS 


Patterns  for  Collar  on  Straight  Bonnet 

Fig.  119  shows  how  the  pattern  for  a  collar  on  a  straight  bon- 
net and  the  opening  in  the  side  of  the  bonnet  are  obtained.  The 
plan  and  elevation  are  clearly  indicated,  as  is  the  method  of  ob- 
taining the  miter  line  from  the  plan  after  the  proper  pitch  of 
the  collar  has  been  shown.  It  will  be  noticed  that  in  the  draw- 
ing the  diameter  of  the  collar  is  out  of  all  proportion  to  the  size 


HALF  PATTERN 
FOR  COLLAR, 


3  I        I       23 
454 


\HALr  ELEVATION. 

i| 
it 


PLAN 
i       "k     ' 


Fig.  119 — Method  of  Obtaining  Patterns  for  Collar  and  Opening  to  Be 
Cut  on  a  Straight  Bonnet. 

of  the  bonnet.  This  has  been  done  so  as  to  clearly  show  how 
the  points  of  intersection  have  been  obtained.  The  method  of 
obtaining  the  shape  of  the  opening  is  so  clearly  shown  at  the 
left  of  the  elevation,  also  that  of  the  collar  above,  as  to  require 
no  further  description. 

Fastening  the  Collars  to  the  Bonnet 

Figs.  1 20,  121  and  122  show  how  the  collars  are  secured  to 
the  three  styles  of  bonnets  previously  described.  Fig.  120  shows 
a  view  of  the  finished  collar  ready  to  be  secured  to  the  pitched 
bonnet,  which  is  constructed  as  shown  in  Fig.  121,  where  A 
shows  the  bonnet  and  B  the  collar.  On  the  collar  itself  along 
the  miter  cut  a  half  inch  edge  a  is  flanged  out,  then  on  the  inside 


FURNACE  FITTINGS  185 

a  one  and  one-half  inch  strip  is  riveted  as  shown  at  b.  The 
collar  is  inserted  in  the  opening  in  the  bonnet,  and  the  notched 
flange  turned  snugly  around  as  indicated  at  c,  which  secures 
the  collar.  If  desired  a  few  rivets  can  be  placed  in  the  flange  a. 


Fig.  121 — Method  of  Securing 
Collar  to  Bonnet. 

Fig.  120 — Finished  Col-  Fig.  122 — Finished  Col- 

lar for  Pitched  Bonnet.  lar  for  Flat  Casing  Top. 

The  same  method  may  be  employed  for  the  collars  in  the  straight 
bonnet.  Where  elbows  are  connected  direct  to  the  flat  top  cas- 
ing as  shown  in  Fig.  117,  the  co^ars  are  prepared  as  shown  in 
Fig.  122,  and  secured  to  the  casing  top  as  just  described. 

Elbows 

When  making  the  connections  from  the  bonnet  to  the  pipes, 
elbows  are  usually  employed,  and  while  adjustable  elbows  can 
be  purchased  from  dealers,  it  is  well  to  know  the  short  rules  for 
laying  out  the  various  pieced  elbows,  as  odd  sizes  may  be  re- 
quired, and  elbows  can  be  made  up  in  spare  time.  Fig.  123  shows 
the  various  positions  to  which  a  four  pieced  elbow  of  this  type 
can  be  adjusted  to  suit  any  condition  which  may  arise. 

When  patterns  for  elbows  are  to  be  laid  out,  a  short  method 
can  be  employed  for  finding  the  rise  of  the  miter  line  by  means 
of  a  protractor,  as  shown  in  Fig.  124.  This  rule  is  applicable  to 
any  size  elbow  no  matter  how  many  pieces  it  contains  or  what 
angle  it  is  intended  to  have  when  completed.  For  an  example, 
we  will  assume  that  the  rise  of  the  miter  line  is  to  be  found  for 
a  four  piece  elbow,  whose  throat  is  to  be  8  inches,  its  diameter 
6  inches  and  whose  angle  is  to  be  90  degrees  when  completed. 
In  diagraming  all  pieced  elbows,  each  end  piece  counts  one  as 
a  unit  of  degrees  and  each  middle  piece  counts  as  two.  Thus 
in  a  four  pieced  elbow  we  have  I +2 +2+ I  =6.  Six  is  then 
the  divisor.  As  the  completed  elbow  is  to  have  90  degrees  when 
completed,  the  rise  or  the  degree  of  the  miter  line  is  found  by 


i86 


FURNACE  FITTINGS 


dividing  90  by  6.  Thus  15  degrees  is  the  rise  of  the  miter  line 
shown  in  the  illustration.  This  single  miter  line  is  all  that  is 
required  in  developing  the  full  set  of  patterns.  The  cut  of  the 
completed  elbow  is  given  to  show  that  if  the  first  miter  line  is 
15  dgrees  from  the  base  line,  the  second  miter  line  would  be 


Fig.  123 — Various  Positions  to  Which  a  Four- Piece  Adjustable  Elbow 

Can  Be  Set. 

45  degrees,  the  third  75  degrees,  and  the  quadrant  shown  would 
equal  90  degrees,  thus  providing  the  rule  that  each  middle  piece 
contains  double  the  angle  of  each  end  piece. 

Applying  the  Rule 

In  Fig.  125  is  shown  how  this  rule  is  applied  in  practice  to 
develop  the  pattern  for  a  four-pieced  90  degree  elbow,  regard- 
less of  its  diameter,  throat  or  number  of  pieces.  First  draw 
any  horizontal  line  as  A  B.  From  any  point  at  C  erect  the  verti- 
cal line  C  D.  Using  C  as  a  center,  draw  a  quadrant  of  any 
size  as  a.  b.  If  a  protractor  is  handy,  place  the  center  of  the 
protractor  upon  C  and  draw  the  angle  of  15  degrees  as  shown. 
If  no  protractor  is  at  hand  this  angle  of  15  degrees,  or  any  other 
angle,  can  be  found  as  follows :  Knowing  that  Jhe  divisor  is  6, 


FURNACE  FITTINGS 


divide  the  quadrant  a  b  into  six  parts  as  shown,  and  through 
the  first  part  draw  the  line  C  E  indefinitely,  which  represents  an 
angle  of  15  degrees.  Now  set  off  on  A  B,  the  length  of  the 
throat,  as  indicated  by  C  i,  and  from  i  set  off  I  7,  the  diameter 


Fig.  124 — Finding  the  Degree  of  the  Miter  Line. 

of  the  desired  elbow.  On  i  7  place  the  semicircle  shown,  which 
divide  into  equal  spaces,  from  which  points  erect  lines  intersecting 
the  miter  line  C  E  as  shown.  Now  take  twice  the  girth  of  the 

NET  PATTERNS 


K' 


2\\         i/6 

3^L^5 

Fig.    125 — Applying  the   Rule   to   Developing   the    Patterns    for   a   Four- 
Piece  Elbow. 

semicircle  i  to  7  and  place  it  on  the  line  A  B  from  i  to  7  to  i, 
from  which  points  erect  perpendiculars,  intersecting  them  by 
lines  drawn  parallel  to  A  B  from  similar  intersections  on  the 
miter  line  C  E.  Trace  a  line  through  points  thus  obtained,  then 


1 88  FURNACE  FITTINGS 

will  i  H  J  K  i  be  the  miter  pattern  for  the  end  piece.  The  full 
set  of  four  patterns  can  be  obtained  from  one  piece  of  metal 
without  waste,  as  follows:  H  M  and  K  L  are  each  made  equal 
to  twice  J  7.  H1  M  and  K1  L  are  made  equal  to  J  P1,  while 
H1  N  and  K1  O  are  equal  to  H  i  or  K  i,  which  completes  the 
net  patterns. 

Elbows  Less  Than  Right  Angles 

If  the  elbows  were  taken  from  a  flat  top  casing,  as  shown 
in  Fig.  117,  a  pitch  would  be  required  in  the  top  piece  of  the 
elbow,  and  assuming  that  the  elbows  were  to  be  completed  having 
angles  of  80  degrees,  the  rise  of  the  miter  line  would  be  obtained 
as  indicated  in  Fig.  126,  in  which  the  two  end  pieces  as  a  whole 
count  2,  and  the  two  middle  pieces  count  4,  making  a  total  of 
6.  As  the  completed  elbow  is  to  contain  80  degrees,  then 
80/6=13  1/3  degrees,  which  is  the  rise  of  the  miter  line. 

Seaming  the  Circular  Joints 

When  the  patterns  for  the  elbows  have  been  laid  out,  allow- 
ance must  be  made  for  seaming.  The  method  of  seaming  the 
circular  joints  of  the  elbow  is  indicated  in  Fig.  127.  It  will  be 
noticed  that  one  end  of  each  piece  has  a  single  edge  and  the 
other  end  a  double  edge.  When  elbows  are  made  in  large  quan- 
tities, special  machine  outfits  can  be  obtained  for  making  pieced 
elbows,  which  consist  of  squaring  shears,  curved  shears  and 
knives  for  cutting  the  various  sections,  press  and  dies  for  punch- 
ing rivet  holes  in  the  longitudinal  joints,  folder  and  groover  for 
lock  seams,  forming  rolls,  burring,  double  edging  and  seam  clos- 
ing machine  for  making  the  circular  joints  and  a  beading  and 
crimping  machine  for  contracting  one  end  of  each  elbow. 

Oval  Elbows 

In  addition  to  the  round  elbows  most  often  used,  oval  elbows 
are  sometimes  required  in  the  partitions  to  connect  with  the  warm 
air  pipes.  These  oval  pieced  elbows  are  sometimes  joined  to- 
gether on  the  "flat"  or  on  the  "sharp."  Fig.  128  shows  a  three 
pieced  elbow  joined  together  on  the  "flat."  In  developing  the 
pattern  for  an  elbow  of  this  kind,  the  profile  of  the  elbow  must 
be  placed  as  indicated  in  Fig.  129,  where  the  method  of  develop- 
ing a  three  pieced  "oval"  elbow  on  the  flat  is  shown.  Draw 
any  horizontal  line,  on  which  locate  E,  which  use  as  a  center 
and  draw  any  size  quarted  circle  as  shown,  representing  90  de- 
grees. Divide  this  in  four  parts  of  22^  degrees  each,  and  from 
E  draw  a  line  through  the  22^  degrees  indefinitely  as  shown 
Lay  off  the  throat  distance  E  F,  and  below  this  line  in  the  posi- 
tion shown  place  the  profile  H,  and  extend  lines  upward  until 


FURNACE  FITTINGS 


189 


they  cut  the  miter  line  at  e  and  /.  From  this  point  the  method 
of  procedure  is  the  same  as  that  shown  in  Fig.  125.  This  will 
produce  an  elbow  on  the  "flat."  Fig.  130  shows  a  three  pieced 


Fig.  126 — An  So-Degree 
Four-Piece  Elbow. 


I *_  _ 

Fig.  127 — Locking 
the   Circular  Joints. 


Fig.  128 — Three-Piece 
Oval  Elbow  on  the 
"Flat." 


Fig.  120— Placing  the 
Profile  for  Develop- 
ing the  Patterns  for  a 
Three-Piece  Oval  El- 
bow on  the  "Flat." 


Fig.  130 — Three-Piece 
Oval  Elbow  on  the 
"Sharp." 


Fig.   131 — Placing  the  Profile  for  Developing 
an  Oval  Elbow  on  the   'Sharp." 


oval  elbow  on  the  "sharp,"  and  in  developing  an  elbow  of  this 
kind  the  profile  must  be  placed  in  the  position  shown  by  C  in 


190  FURNACE  FITTINGS 

Fig.  131,  when  the  method  of  procedure  is  the  same  as  before 
with  only  the  difference  in  the  position  of  the  profile  C  from 
that  of  H  in  Fig.  129.  The  former  produces  an  elbow  on  the 
"sharp"  and  the  latter  an  elbow  on  the  "flat." 

Developing  the  Patterns  for  a  Reducing  Elbow 

Fig.  132  shows  a  view  of  a  three  pieced  90  degree  reducing 
elbow  in  which  the  pipe  A  is  reduced  by  means  of  the  transition 
piece  C  to  the  required  size  B.  In  working  out  this  problem  the 
pipes  A  and  B  are  developed  by  means  of  parallel  lines,  while 
the  middle  transition  C  is  developed  by  triangulation.  How  these 
three  patterns  are  aid  out  is  shown  in  detail  in  Fig.  133.  First 
draw  the  center  line  of  the  elbow  as  shown  by  a  3  8  b,  making 
the  distance  3  8,  twice  that  of  a  3  or  8  fr.L  Extend  3  a  and  8  b 
indefinitely  'as  shown,  upon  which  establish  the  centers  i  and  k 
respectively  and  describe  the  profile  of  the  small  pipe  F  and 
large  pipe  E.  at  sufficient  distances  from  a  and  b  of  both  arms 
of  the  elbow.  Obtain  the  miter  lines  of  the  elbow  by  using  3 
and  8  on  the  center  line  as  centers  and  describe  the  arcs  c  d  and 
/  g  respectively.  Now,  with  any  desired  greater  radius  and  using 
c  and  d,  also  /  and  g  as  centers,  describe  arcs  intersecting  each 
other  at  e  and  at  h.  Draw  lines  indefinitely  through  e  3  and  h  8. 
Intersect  the  former  by  horizontal  lines  drawn  through  i  and  5 
in  the  profile  F,  and  the  latter  by  vertical  lines  drawn  through 
6  and  10  in  the  profile  E.  Connect  i  with  10  and  5  with  6  to 
form  the  middle  piece  B.  Then  ABC  shows  the  side  elevation 
of  the  reducing  elbow. 


A 
Fig.   132 — A  Reducing  Elbow. 

Divide  both  the  half  profiles  F  and  E  in  the  same  number  of 
equal  parts,  as  shown  from  I  to  5  and  6  to  10  respectively,  and 
from  these  various  small  figures  draw  lines  parallel  to  the  center 
lines  of  the  pipe  until  they  intersect  the  miter  lines  as  shown  by 
simliar  numbers.  The  half  patterns  for  the  pipes  A  and  C  are 
developed  in  the  usual  manner  as  shown  and  need  no  further 
explanation. 


FURNACE  FITTINGS 


191 


The  pattern  for  the  middle  section  C  will  be  laid  out  by  tri- 
angulation.  No  sections  need  be  developed  on  the  miter  lines 
i  5  or  6  10  in  elevation,  as  correct  measurements  for  the  sev- 
eral spaces  can  be  taken  from  the  miter  cuts  i'  5'  and  6'  10'  in 
the  patterns.  Connect  points  in  i  5  with  those  in  6  10  as  shown 


1 2  3 

DIAGRAM    OF    TRUE. 


Fig.  133 — Developing  the  Patterns  for  a  Pieced  Reducing  Elbow. 

by  the  dotted  lines.  These  lines  then  represent  the  bases  of 
sections  at  each  end  of  which  prpendiculars  will  be  erected  whose 
altitudes  will  equal  the  various  hight  in  the  semi-profiles  F  and 
E  as  shown  in  diagram  J.  For  example,  to  find  the  true  length 
of  the  line  4  8  in  B,  set  off  its  length  as  shown  from  4  to  8  on 


192 


FURNACE  FITTINGS 


any  horizontal  line  as  L  M  in  J,  and  at  4  and  8  erect  the  per- 
pendiculars 4  4'  and  8  8'  equal  respectively  to  the  distances  meas- 
ured from  the  center  lines  to  points  4  and  8  in  the  profiles  F  and 
E.  The  distance  from  4'  to  8'  in  J  shows  the  required  length. 
In  a  similar  manner  are  the  remainder  of  true  lengths  found. 


S/DE  VIEW 
I 
I 


Fig.  135 — T -Joint  Between 
Pipes  of  Equal  Diameter. 


PATTERN 


Fig.  134 — T-Joint  Between 
Pipes  of  Equal  Diameter. 


The  pattern  is  next  in  order.  As  5  6  in  B  shows  its  true 
length,  set  off  this  distance  as  shown  by  5'  6'  in  the  pattern 
at  H.  Now  with  radius  equal  to  6'  7'  in  the  half  pattern  for 
C,  and  with  6'  in  H  as  center,  describe  the  arc  near  7',  which 
intersect  by  an  arc  struck  from  5'  as  center  and  5'  7'  in  the  true 
lengths  in  J  as  radius,  now  with  5'  in  the  pattern  H  as  center  and 
5'  4  in  the  pattern  A  as  radius  describe  the  arc  shown  near  4', 
which  intersect  by  an  arc  struck  from  7'  as  center  with 
7'  4'  in  the  diagram  J  as  radius.  Proceed  in  this 
manner,  using  alternately,  first  one  of  the  spaces  along  the  miter 


FURNACE  FITTINGS 


193 


cut  in  half  pattern  for  C,  with  the  proper  true  length  in  J  to 
form  the  larger  end  of  the  pattern;  then  one  of  the  spaces  along 
the  miter  cut  in  the  half  pattern  for  A  with  the  proper  length  in 


Fig.  136 — A  Round  Header. 

J  to  form  the  smaller  end  of  the  pattern,  until  all  spaces  have 
been  used  and  the  pattern  has  been  developed.  Laps  must  be 
allowed  for  seaming  as  before  explained. 


454 
32123 


OPENING 
>H\D    \ 

^        V 

H-4 


Fig.   137 — Patterns  for  T-Joint  Between  Pipes  of  Unequal  Diameters 
at  Other  Than  a  Right  Angle. 

Fig.  134  shows  a  view  of  a  T  joint  where  the  three  openings 
have  equal  diameters.  The  rule  employed  for  developing  the 
patterns  is  explained  in  connection  with  Fig.  135,  in  which  an 
elevation  of  the  joint  is  shown.  When  the  sizes  of  the  two 


194  FURNACE  FITTINGS 

branches  are  the  same,  no  projections  of  points  are  required 
in  finding  the  miter  line;  all  that  is  required  is  to  intersect  the 
centers  of  the  two  branches  as  at  D  and  then  draw  the  miter 
lines  C  D  E.  The  pattern  for  the  branch  A  is  obtained  in  the 
usual  manner.  The  girth  of  A  is  placed  at  right  angles  to  the 
lines  of  the  pipe  as  shown,  the  usual  measuring  lines  drawn  and 
intersected  as  shown  resulting  in  the  pattern  for  A. 

The  shape  of  the  opening  to  be  cut  in  the  main  pipe  B  is 
obtained  by  taking  one  half  of  the  girth  of  pipe  as  indicated  by 
a  b  c  (or  3  to  i  to  3  in  the  profile  for  A,  since  both  pipes  are 
similar)  and  placing  it  at  right  angles  to  B  as  shown,  and  then 
intersecting  the  measuring  lines  from  the  divisions  in  the  pro- 
file, all  as  shown.  This  short  method  can  only  be  followed  when 
the  two  branches  have  the  same  diameters.  Fig.  136  shows  a 
round  header  with  lead  off  collars  at  a  and  b.  The  principles 
shown  in  Fig.  135  can  be  applied  to  Fig.  136. 

T  Joint  Between  Pipes  of  Unequal  Diameters  at  an  Angle 

When  a  branch  is  to  be  taken  from  a  main  pipe  at  an  angle, 
the  branch  being  of  smaller  diameter  than  the  main,  the  rule 
to  follow  regardless  of  what  the  diameters  or  angle  may  be,  is 
shown  in  Fig.  137  in  which  A  and  A1  show  the  profile  of  the 
branch  pipe  and  B  the  profile  of  the  main.  D  C  shows  the  side 
view  of  the  T,  the  branch  C  in  this  case  being  placed  at  an  angle 
of  45  degrees.  First  divide  both  profiles  A  and  A1  into  the 
same  number  of  equal  parts,  placing  the  numbers  in  the  posi- 
tion shown.  From  the  points  in  A1  draw  lines  parallel  to  the 
lines  of  the  pipe  until  they  intersect  the  profile  of  the  main  pipe 
as  shown,  from  which  vertical  lines  are  drawn  and  intersected 
by  lines  drawn  parallel  to  the  pipe  C  from  the  numbered  points 
in  the  profile  A.  Through  the  intersection  thus  obtained  trace 
the  miter  line  shown.  The  pattern  for  the  branch  C  is  obtained 
in  the  usual  manner  as  indicated.  To  obtain  the  opening  in  the 
main  pipe  D,  obtain  the  girth  by  using  the  various  spaces  in  the 
end  view  B,  measuring  each  space  separately,  as  they  are  un- 
equal, and  place  them  at  right  angles  to  the  line  of  the  main 
pipe  D  in  the  side  view.  The  usual  measuring  lines  are  now 
drawn,  and  intersected  by  lines  from  points  of  corresponding 
number  shown  in  the  miter  line.  This  gives  the  opening  to  be 
cut  in  the  pipe  D. 

In  Fig.  138  is  shown  a  view  of  a  reducing  T  joint  such  as 
is  sometimes  used  in  trunk  lines  of  heating.  The  method  of 
laying  out  these  patterns  is  shown  in  detail  in  Fig.  139.  First 
of  the  illustration,  and  place  on  either  side  of  the  center  line 
A  B,  the  widths  a  l'  and  b  i  in  their  proper  positions  connect  the 


FURNACE  FITTINGS 


195 


lines  i'  I  extending  them  until  they  meet  at  C.  On  the  line  I  I 
place  the  semi-profile  H,  which  divide  in  equal  spaces  as  shown 
from  i  to  3,  from  which  points  draw  lines  parallel  to  A  B  inter- 
secting the  line  I  I,  From  the  apex  C  draw  radial  lines 


Fig.  138— A  Reducing  T-Joint. 


through  the  points  on  I  I  until  they  intersect  the  profile  of  the 
large  pipe  from  i'  to  3'.  From  these  intersections  at  right  angles 
to  A  B  draw  lines  cutting  the  side  of  the  tapering  pipe  at  i'  2" 
and  3".  These  points  are  used  in  developing  the  pattern  for  the 
taper  joint  in  the  following  manner :  Using  C  as  center  and  C 
i  as  radius,  draw  the  arc  i  3"  ',  upon  which  lay  off  the  girth  of 
twice  the  semi-circle  H  as  shown  by  similar  numbers.  Through 
these  small  figures  draw  radial  lines  from  C,  extending  them 
indefinitely  and  intersecting  them  by  arcs  of  corresponding  num- 
ber struck  from  C  as  center  with  radii  equal  to  C  i',  C  2"  and  C  3". 
A  line  traced  through  points  thus  obtained  as  showrn  by  J  K  L, 
together  with  3" '  3"  will  give  the  net  pattern,  to  which  edges 
must  be  allowed  for  riveting. 

The  shape  of  the  opening  to  be  cut  in  the  cylinder  is  obtained 
from  the  side  view,  which  is  projected  as  follows :  Draw  any 
horizontal  line  as  D  E,  upon  which  locate  the  points  C1,  b'  and 
i  from  similar  points  in  the  end  view.  Draw  the  semi-profile 
H1  and  divide  similar  to  H,  reversing  the  numbers  as  shown. 
From  the  small  figures  in  H1  draw  perpendiculars  to  3  3  inter- 
secting that  line.  Through  the  points  on  3  3  draw  radial  lines 
from  C1,  extending  them  to  intersecting  lines  drawn  at  right 
angles  to  A  B  from  the  similar  numbered  intersections  i'  2'  and 
3'  in  the  end  view  of  large  pipe,  which  gives  the  miter  line  in 
the  side  view.  Now  upon  any  line,  as  F  G  drawn  at  right  angles 
to  the  line  of  the  main  pipe,  place  the  girth  of  large  pipe  as  ob- 
tained from  the  various  divisions  i'  2'  3',  etc.,  in  the  end  view, 
being  careful  to  measure  each  space  separately,  as  they  are  all 


196 


FURNACE  FITTINGS 


unequal.  From  the  points  thus  obtained  on  F  G  draw  measuring 
lines  at  right  angles  to  F  G,  and  intersect  them  by  lines  drawn 
parallel  to  F  G  from  similar  points  in  the  miter  line.  The 
shaded  portion  shows  the  opening  to  be  cut  in  the  main  pipe. 


F    I'  2'    3'    2'  I'  G- 


QPENING  IN 
CYLINDER 


C* 


\    _  _  -  —  -_-rr,r 

TJ          ---  =  •=  *^m~ 

4  -  --•  -      -x7?5f 
^  •*  -  ^  >  ///' 


c-^ 


PATTERN  FOR 

JO//VT: 


Fig.  139 — Laying  Out  a  Reducing  T. 


Construction  of  Riveted  Joints  in  Tees 

The  method  of  constructing  the  joints  shown  in  Figs.  134,  135, 
136  and  138  is  explained  in  Fig.  140,  which  shows  how  the  T 
is  riveted  to  the  main  pipe.  A  flange  a  in  the  diagram  is  turned 
outside  on  the  main  pipe,  while  b  shows  the  flange  turned  out- 
ward on  the  T  through  which  the  rivets  are  placed,  giving  an 
appearance  similar  to  Fig.  138. 

Construction  of  Cold  Air  Shoes 

When  making  the  cold  air  connection  to  the  bottom  of  the 
furnace  a  shoe  is  required.  Two  styles  of  cold  air  shoes  for 


FURNACE  FITTINGS 


197 


connections  to  round  pipe  are  shown  in  Fig.  141.  The  first,  A, 
is  beveled,  while  B  is  made  tapering  to  suit  the  round  pipe.  The 
round  collar  joining  the  shoe  is  constructed  similar  to  Fig.  122, 
but  the  connection  of  the  shoes  in  Fig.  141  with  the  furnace  is 


Fig.  140 — Method  of  Riveting  Reducing  T. 

prepared  as  there  shown,  in  which  a  in  both  views  indicates  the 
tiange  on  the  shoe  proper,  and  b  is  a  separate  flange  riveted 
to  the  inside  of  the  shoe  and  notched  so  as  to  allow  it  to  be  bent 
inward  on  the  casing.  The  shoe  A  is  shown  in  position  on  a 
furnace  in  Fig.  142,  where  the  round  cold  air  pipe  is  also  con- 
nected. 


Fig.  141— Shoes  for  Connections  to  Round  Cold  Air  Pipes. 


In  Fig.  143  is  shown  a  cold  air  shoe  for  inside  air  connection. 
A  is  the  collar  for  the  hall  connection.  A  wire  mesh  is  placed  in 
die  opening  through  which  the  inside  basement  air  is  admitted, 
Flanges  are  placed  at  a  a  for  casing  connections.  In  making  up 
these  shoes  the  corners  are  double  seamed  and  the  curve  at  the 
farther  end  of  the  shoe  suits  the  curvature  of  the  furnace  cas- 
ings. 

Fig.  144  shows  a  galvanized  sheet  melal  shoe  for  rectangular 
pipe.  In  placing  the  collars  or  shoes  on  the  casing  they  must 
always  be  put  on  before  the  casing  is  put  around  the  furnace. 
A  in  Fig.  145  shows  the  shoe  in  position  for  rectangular  cold 
air  duct,  the  method  of  fastening  to  the  casing  being  indicated 


198  FURNACE  FITTINGS 

in  diagram  X,  in  which  A  represents  the  casing  and  B  the  base 
ring.  The  outerflange  of  the  shoe  collar  is  placed  snugly  against 
the  casing  and  the  inner  notched  flange  a  turned  tightly  against 


Fig.  142 — Shoe  Connected  to  Round  Cold  Air  Pipe. 

the  inside  of  the  casing,  as  shown  at  b,  and  riveted.  Sometimes 
a  cast  iron  shoe  is  riveted  or  bolted  to  the  casing  proper,  as 
shown  in  Fig.  146,  holes  being  drilled  along  the  cast  iron  flange 
to  which  the  cold  air  duct  is  bolted. 


Fig.  143 — Cold  Air  Shoe  for 
Inside  Air  Connection. 


Fig.  144— Sheet  Metal  Cold  Air 
Shoe  for  Rectangular  Pipe. 


Pattern  for  Shoe  Connecting  to  Center  of  Furnace 

When  the  cold  air  shoe  is  directed  toward  the  center  of  the 
furnace,  the  pattern  for  same  can  be  laid  out  as  shown  in  Fig. 


FURNACE  FITTINGS 


199 


147,  in  which  A  shows  the  plan  view  of  the  furnace,  whose 
radius  is  D.  B  shows  the  plan  of  the  duct  whose  section  is 
shown  at  C.  Take  the  girth  of  the  duct  C,  from  i  to  2  to  3 
to  4  to  i  and  set  it  off  on  any  horizontal  line  as  shown  just  below. 
Make  the  length  of  the  collar  as  desired,  as  I  a,  and  through  a 


I 


Fig.  J45 — Connecting  Sheet  Metal  Shoe  to  Furnace  Casing. 

draw  the  line  E  F,  parallel  to  i-i.  Through  the  points  2,  3 
and  4  draw  lines  intersecting  E  F  at  a,  b  and  b.  Using  D  as 
radius,  and  a  and  b  on  both  sides  of  the  diagram  as  centers, 
describe  arcs  intersecting  each  other  in  c.  With  the  same  radius 
and  c  and  c  as  centers  draw  the  arcs  a  b  and  b  a,  which  com- 
plete the  pattern  or  layout.  When  the  duct  is  of  such  size  that 


Fig.  146 — Cast  Iron  Shoe  for  Cold  Air  Connection. 

it  cannot  be  made  up  of  one  piece    the  corners  are  then  double 
seamed,  making  it  up  in  either  two  or  four  pieces. 

Pattern  for  Shoe  Connecting  to  One  Side  of  Furnace 

When  the  cold  air  duct  connects  to  the  casing  to  one  side 
or  off  the  center,  as  shown  in  plan  in  Fig.  148,  the  layout  or 
pattern  is  obtained  as  just  below.  In  the  cut  A  is  the  furnace, 
B  the  duct  or  shoe,  and  C  its  section.  Take  the  girth  of  C  as 
before  and  place  it  on  any  straight  line,  as  shown  below,  and 
at  the  desired  distance  draw  any  line  as  E  F.  At  right  angle  to  the 
duct  line,  from  the  intersection  with  the  casing  at  B,  draw  the 


200 


FURNACE  FITTINGS 


line  B  a.     Take  the  distance  from  a  to  b,  which  represents  the 
corners  3  and  4  in  the  section,  and  set  it  off  on  lines  drawn 


Fig.  147 — Layout  of  Shoe  for  Concentric  Cold  Air  Pipe. 


Fig.  148— Layout  of  Shoe  for  Excentric  Cold  Air  Pipe. 


FURNACE  FITTINGS 


201 


through  3  and  4,  measuring  from  the  line  E  F,  as  shown  from 
a  to  b'.  Now  using  the  proper  radius  H,  and  b'  and  c  in  the 
layout  as  centers,  intersect  arcs  at  d.  Then  using  d  and  d  as 
centers  with  the  same  radius,  describe  the  arcs  c  b'  as  shown. 
This  gives  the  layout  for  a  duct,  intersecting  the  shoe  or  casing 
as  shown  in  plan.  Flanges  must  be  ollowed  for  riveting  and 
seaming. 


Fig.  149 — Showing  How  Friction  Is  Avoided. 


Frictionless  Cold  Air  Duct  Elbows 

When  connecting  the  outside  cold  air  duct  all  possible  friction 
should  be  eliminated.  All  elbows  and  bends  should  be  curved 
as  shown  by  A  and  B  in  Fig.  149.  A  general  rule  which  can 
l)e  employed  in  obtaining  the  radius  for  describing  the  throats 


Fig.   150 — Rule  for  Obtaining  Radii  for  Curves. 


of  the  elbows  or  bends  is  shown  in  Fig.   150.     Whatever  the 
width  of  the  pipe  may  be,  that  width  should  be  the  radius  with 


2O2 


FURNACE  FITTINGS 


which  to  describe  the  throat  of  the  bend  as  shown  by  B  A.  To 
this  radius  is  added  the  width  of  the  pipe  which  gives  the  radius 
B  C  for  describing  the  heel  C.  If  the  width  of  the  duct  is  18 
inches,  the  radius  of  the  throat  becomes  18  in.  and  that  of  the 
heel  36  in. 

Seaming  Cold  Air  Duct  Elbows 

There  are  two  methods  of  seaming  the  corners  of  the  elbows 
in  cold  air  duct  work;  the  first  method  is  shown  by  A  in  Fig. 
151,  in  which  the  top  and  bottom  of  the  elbows  have  a  formation 


m 


TOP    OR 
GOT  TOM 


TOP  O/? 
BOTTOM 


B 


Fig.  151— Seaming  the  Cold  Air  Duct  Elbows. 

as  indicated  by  c,  while  the  sides  or  elbow  curves  have  a  single 
edge.  The  lock  is  first  bent  as  indicated  by  x,  and  after  the 
sides  are  inserted  in  the  groove  a  ''dolly"  is  held  on  the  inside 


Fig.  152 — Floor  Register  Box. 

corner  c  and  x  turned  down  with  the  mallet  as  indicated  by  a. 
The  second  method  B  is  the  regulation  method  but  requires  more 
time  than  the  former. 

Developing  and  Constructing  Floor  Register  Boxes 

Register  boxes  are  constructed  of  single  and  double  walls. 
Those  usually  employed  are  of  the  single  wall  type  shown  in 
Fig.  152,  and  are  made  in  various  sizes.  The  size  of  the  register 
box  is  determined  by  the  size  of  pipe  to  which  it  will  be  con- 
nected. Floor  registers  are  usually  connected  to  round  pipes. 
To  find  the  proper  size  box  from  the  round  pipe,  the  following 
rule  is  usually  employed : 


FURNACE  FITTINGS 


203 


Rule  for  Determining  the  Size  of  the  Register  Box 

Find  the  area  of  the  given  round  pipe;  then  double  it  and  find 
the  stock  size  of  register  near  to  this  area,  and  make  register 
box  to  fit.  For  example,  if  the  round  pipe  is  10  inches,  its  area 
is  78.54,  which  doubled  gives  157.08.  The  nearest  stock  size 
register  is  10"  X  16",  which  equals  160,  then  ioj/6"  X  16^6"  is 
the  proper  size  register  box  to  use.  The  one-eighth  inch  added 
to  the  size  of  the  register  is  for  play  room. 

FLANGE 


Fig.  153 — Net  Patterns  for  Floor  Register  Box  in  One  Piece. 


Table  of  Areas  of  Round  Pipes  and  Registers 

The  following  table  gives  a  safe  guide  to  determine  the  cor- 
rect sizes  of  registers  to  use  with  the  standard  sizes  of  round 
pipes : 


TABLE  OF  AREAS  OF  ROUND  PIPES  AND  REGISTERS. 


Dimensions 
of  pipe. 


12 

14" 
16" 
18" 

20" 
22 

24' 


Area  in  square 
inches. 


Size  of  register 
required. 

50    8X12 

63    9X14 

78    10X16 

113    14X16 

154    16X20 

201    18X24 

254    20X26 

3M    24X27 

380    24X32 

452    30X30 


2O4  FURNACE  FITTINGS 

Pattern  for  Floor  Register  Box  in  One  Piece 

Fig.  153  shows  how  a  floor  register  box  is  developed  in  one 
piece  when  it  is  of  such  size  that  it  can  be  made  from  one  sheet 
of  tin  plate.  In  laying  out  register  boxes,  a  slight  taper  should 
be  given  as  shown  in  Fig.  152.  In  Fig.  153  the  method  of  de- 
veloping the  box  is  as  follows:  Draw  the  required  size  of  the 
rectangle  abed  and  draw  the  two  diagonal  lines  intersecting 
each  other  at  e,  which  is  the  center  point  with  which  to  describe 
the  opening  to  receive  the  collar.  Parallel  to  the  sides  of  the 
rectangle,  place  the  hight  of  the  box  as  shown,  to  which  allow 
a  flange.  Extend  the  sides  and  ends  of  the  box  and  allow  the 
taper  as  indicated  by  i  h  and  2  /  and  draw  the  miter  lines  to 
the  corners  a  b  c  and  d.  Edges  must  be  allowed  for  double 
seaming. 

Patterns  for  Floor  Register  Box  in  Four  Pieces 

When  the  register  box  is  of  a  large  size  the  register  box  can 
be  made  up  in  four  pieces  as  indicated  in  Fig.  154,  where  a  b 


Fig.  154 — Net  Patterns  for  Floor  Register  Box  in  Four  Pieces. 

and  b  c  show  respectively  the  length  and  width  of  the  register, 
while  a  i  and  b  i  show  the  hight  of  the  sides,  the  flare  being 
indicated  by  i  I.  To  obtain  the  bottom  of  the  box  on  each  quar- 
ter pattern,  a  rectangular  bottom  should  be  drawn  on  the  bench 
or  elsewhere,  of  the  desired  size  or  as  long  as  a  b  and  as  wide 
as  b  c  similar  to  a  b  c  d  in  Fig.  153.  Then  with  a  radius  equal 
to  b  e  and  using  a,  b,  b  and  c  in  Fig.  154  as  centers,  describe 
arcs,  cutting  each  other  at  e  and  e" .  Then  using  c  i  in  Fig.  153 
as  radius  and  e  and  e"  in  Fig.  154  as  centers  draw  the  arcs  i' 
and  i"  as  shown,  which  intersect  by  the  diagonals  drawn  from 
a  and  b  to  the  center  e  and  from  b  and  c  to  the  center  e".  Edges 
must  be  allowed  for  double  seaming  the  corners  and  bottom. 
Sometimes,  however,  the  boxes  are  made  in  five  pieces — that  is, 
the  four  sides  and  a  separate  bottom. 

Quick  Method  of  Joining  Collar  to  Register  Box 

When  the  corners  of  the  register  box  shown  in  Fig.  153  have 
been  doubled   seamed,  the  collar  can  be   joined   to   the  bottom 


FURNACE  FITTINGS 


205 


by  a  quick  method  as  shown  in  Fig.  155,  in  which  the  collar  is 
beaded  about  one-half  inch  below  the  end,  using  a  quarter  inch 


-.  —  * 

Fig.  155—  Two  Methods  of  Joining  Pipe  Collar  to  Register  Box. 


bead.   ^The  half-inch  flange  above  the  bead  is  now  notched  about 
every  inch,  after  which  the  collar  is  placed  through  the  bottom 


/7/PJr       METHOD 
I  ! 

& r-    r- 


J          j  1 

First  \   Second.        \     ftnat. 

Operation.    ^  ^ 


SECOA/& 


156—  Quick  Method  of  Joining  Collar. 


of  the  register  box,  as  at  B,  then  pressing  the  bead  tightly  against 
the  bottom  of  the  box,  the  notched  flanges  are  turned  down  firmly 
as  at  a  a. 


206 


FURNACE  FITTINGS 


Two   Other  Methods   of  Constructing  Register  Boxes 

In  Fig.  156  are  shown  two  other  methods  of  joining  the  collar 
to  the  boxes,  each  method  being  shown  in  three  operations.  In 
the  first  method  A  shows  a  section  of  a  register  box  with  the 
edge  A  turned  up  around  the  circular  opening  in  the  square 
bottom.  On  the  collar  B  an  edge  is  turned  outward  on  the 
burring  machine  as  shown.  This  collar  B  is  then  slipped  over 
the  edge  A,  as  shown  in  the  second  operation,  the  lock  closed 
with  the  flat  plyers.  The  box  is  now  set  on  the  square  head 
stake  at  a  and  double  seamed  with  a  mallat  as  shown  by  d  in  the 
final  method.  The  first  operation  of  the  second  method  an  edge 
is  turned  downward  around  the  circular  opening  in  the  flat 
bottom,  and  F  shows  an  edge  turned  inward  around  the  collar. 
The  collar  is  now  placed  inside  of  the  edge  E  and  E  turned 
over  as  shown  at  H  in  the  second  operation.  The  lock  is  then 
turned  down  and  double  seamed  as  shown  at  b  in  the  third 
operation. 


A-- 




Sect -/on    on     A~& 

Fig.   157 — Construction  of  Combination   l.eader  and  Register  Box. 


Construction  of  Combination  Header  and  Register  Box 

In  the  upper  part  of  Fig.  157  is  shown  a  view  of  a  combina- 
tion header  and  register  box.  The  register  box  is  joined  to  the 
headed  oval  stack  as  shown,  the  box  collar  being  of  sufficient 
depth  to  run  flush  with  the  finished  plaster  line  of  the  partition. 
The  method  of  joining  the  collar  to  the  stack  is  shown  in  the 
cut  below  which  represents  a  section  through  A  B.  Note  that 
the  collar  has  a  doubled  flange  at  a,  also  a  projecting  flange  b. 
The  stack  is  cut  out  to  the  required  size,  the  collar  inserted  and 
b  turned  over  as  indicated  by  c. 


FURNACE  FITTINGS 


207 


Boots  or  Wall  Pipe  Starters 

Wall  pipe  starters  are  known  in  some  shops  as  "boots"  or 
"shoes/'  Fig.  158  shows  a  box-shaped  starter  connecting  to 
two  registers.  There  are  various  styles  of  starters  but  those  most 
generally  used  on  first  class  jobs  are  known  as  "box  shaped" 
and  "frictionless."  Care  should  be  taken  in  designing  the  starter 


Fig.  158 — Box-Shaped  Starter  Connecting  to  Two  Registers. 

previous  to  developing  the  patterns,  that  easy,  graceful  sweeps 
are  obtained  to  facilitate  the  flow  of  air  and  avoid  friction.  Fig. 
159  shows  nine  styles  of  box  shaped  starters  which  cover  designs 
for  almost  any  case  that  may  arise.  In  making  up  these  styles 
of  starters  the  pattern  shape  is  pricked  direct  from  the  drawing 
and  edges  allowed  for  double  seaming,  the  round  collars  being 
attached  as  shown  in  a  previous  article.  A  frictionless  round 
to  "oval"  starter  is  shown  in  Fig.  160.  This  same  style  of  fric- 
tionless starter  is  also  made  up  for  rectangular  risers  instead  of 
"oval,"  as  will  be  explained. 

Developing  the  Pattern  for  a  Round  to  "Oval"  Frictionless 

Starter 

The  method  used  for  laying  out  the  pattern  for  the  round  to 
oval  starter  is  shown  simplified  in  Fig.  161.  According  to  this 
method  the  lines  of  the  elevation  are  used  as  base  lines  and  the 


208 


FURNACE  FITTINGS 


Fig.  159 — Nine  Styles  of  Box-Shaped  Starters. 


FURNACE  FITTINGS  209 

various  heighths  in  the  semi-profiles  as  altitudes,  when  funding  the 
true  lengths.  The  first  step  is  to  draw  the  elevation  of  the  starter 
or  boot  as  shown  by  3,  4,  4",  3",  on  either  end  of  which  place 
the  semi-profiles  of  the  round  and  oval  or  oblong  pipes  as  shown. 
As  both  halves  of  the  starter  are  alike  it  is  only  necessary  to 


Fig.  160 — Round  to  Oval  Frictionless  Starter. 

develop  one-half  and  duplicate  it.  The  shaded  sections  in  the 
drawing  show  the  half  profiles.  In  dividing  the  half  profiles  in 
practice  more  spaces  must  be  used  than  are  shown.  In  this  case 
the  upper  and  lower  quadrants  have  been  divided  into  two  spaces 
each,  as  shown  by  the  small  figures  I  to  3  and  4  to  6.  From 
these  small  figures  I  to  3  at  right  angles  to  3  3"  and  from  points 
4  to  6  at  right  angles  to  4  4",  lines  are  drawn  intersecting  the 
lines  3-3"  at  i'  2'  and  4  4"  at  5'  6'.  Connect  these  intersections 
by  lines  6'  to  i'  to  5'  to  2'  and  to  4,  which  lines  will  represent 
the  bases  of  sections  to  be  constructed,  whose  altitudes  are  equal 
to  the  various  hights  of  points  of  corresponding  number  in  the 
semi-profiles.  Take  the  various  lengths  in  elevation  from  6'  to 
i',  bases  i'  to  5',  5'  to  2'  and  2'  to  4  and  set  them  off  as  shown  by 
corresponding  numbers  on  the  horizontal  line  A  B.  From  these 
points  erect  lines  equal  in  hight  to  the  corresponding  altitudes  in 
the  semi-profiles.  As  point  4  in  the  semi-profile  has  no  hight 
over  the  base  line  4-4",  then  4  remains  on  the  line  A  B.  Con- 
nect the  various  points  thus  set  off,  which  will  show  the  true 
lengths  desired.  As  the  seam  is  usually  placed  along  the  ends 
3-4  and  3"-4"  in  elevation,  the  half  pattern  can  be  developed  as 
follows :  Draw  any  straight  line  i  i  in  the  pattern  equal  to  i  i" 
in  the  elevation;  then  using  1-6  in  the  true  length  as  radius,  and 
i  and  i  in  the  pattern  as  centers  describe  arcs  intersecting  each 


210 


FURNACE  FITTINGS 


FURNACE  FITTINGS  211 

other  at  6.  With  6  5  in  the  semi-profile  as  radius  and  6  in  the 
pattern  as  center,  describe  the  arcs  on  both  sides  at  5  and  5  of 
the  pattern  which  intersect  by  arcs  struck  from  I  as  centers 
and  i  5  in  the  true  lengths  as  radius.  With  i  2  in  the  semi- 
profile  as  radius  and  I  and  i  in  the  pattern  as  centers,  describe 
the  arcs  2  and  2,  which  intersect  by  arcs  struck  from  5  and  5  as 
centers  and  5  2  in  the  true  lengths  as  radius.  Proceed  in  this 
manner,  using  alternately,  first  the  division  in  the  round  profile, 
then  the  proper  true  length ;  the  division  in  the  oval  profile,  then 
again  the  proper  true  length,  until  the  line  3  4  in  the  pattern 
has  been  obtained,  which  equals  3  4  in  elevation,  its  true  length. 
Trace  a  line  through  points  thus  obtained  in  the  pattern  which 
will  give  the  layout  for  the  half  pattern,  to  which  edges  must 
be  allowed  for  seaming  purposes. 

Various  Styles  of  Frictionless  Starters 

Fig.  162  shows  five  styles  of  frictionless  starters  which  can 
be  used  for  any  condition  which  may  arise.  The  principles  to 
be  used  in  developing  the  patterns  for  these  starters  are  similar 
in  every  respect  to  that  shown  in  Fig.  161.  Care,  however, 
must  be  taken  in  placing  the  semi-profiles,  as  clearly  shown  in 
the  diagram  in  Fig.  163,  where  the  various  starters  are  num- 
bered to  correspond  to  those  shown  in  Fig.  162.  It  will  be 
noticed  that  the  inlets  are  round,  while  the  outlets  or  stack  con- 
nections are  rectangular.  This  makes  the  methods  of  develop- 
ment as  simple  as  that  shown  in  Fig.  161.  In  this  case  it  is 
only  necessary  to  measure  one  altitude  as  c  d  in  the  diagrams 
in  Fig.  163,  whereas  in  Fig.  161  the  altitudes  varied,  owing  to 
the  curve  at  i  2  3.  After  the  elevations  of  the  starters  have 
been  drawn,  the  semi-profiles  are  placed  as  shown  in  Fig.  163. 
While  the  various  hights  must  be  taken  in  the  semi-round  pro- 
files as  in  the  previous  development,  it  is  only  necessary  to  take 
the  hight  marked  c  d  in  all  the  diagrams,  for  the  rectangular 
profiles.  The  elbow  A  is  joined  to  starter  number  5  to  pro- 
duce the  starter  shown  by  5  in  Fig.  162.  After  the  patterns 
have  been  developed  in  Fig.  163,  two  inches  should  be  added  to 
the  rectangular  end  of  the  patterns,  to  act  as  a  collar,  to  receive 
the  slip  to  which  the  pipe  line  is  connected. 

Offset  Boot 

Fig.  164  shows  a  perspective  view  of  an  offset  boot  round  to 
"oval."  In  developing  the  patterns  for  this  style  of  boot,  the 
upper  and  lower  pipes  are  developed  by  parallel  lines,  while  the 
central  piece  is  laid  out  by  triangulation.  The  principles  which 


212 


FURNACE  FITTINGS 


will  be  employed  can  be  applied  to  this  or  any  other  style,  re- 
gardless of  what  the  profiles  of  the  pipes  may  be. 


Fig.   162 — Five    Styles  of  Frictionless   Starters. 

Developing  the  Patterns 

This  is  shown  in  detail  in  Fig.  165,  in  which  the  center  line 
of  the  boot  is  first  drawn  as  shown  by  a  3'  8'  e,  making  the 
angles  as  desired.  Bisect  these  angles  to  obtain  a  true  miter 


FURNACE  FITTINGS  213 

line  as  follows :  From  3'  as  center,  with  any  desired  radius,  draw 
short  arcs  intersecting  the  center  line  at  a  and  b ;  then  using  a 
and  b  as  centers,  with  a  radius  slightly  greater  than  before,  draw 
the  arcs  intersecting  at  c,  and  draw  the  miter  line  indefinitely 
from  c  through  3'  as  shown.  In  a  similar  manner  obtain  the 
miter  line  /  6'  by  means  of  the  arcs  d,  e  and  /.  Now  place  the 
half  profile  of  the  round  pipe  at  the  lower  end  of  the  boot,  on 
the  line  I  5,  and  the  half  profile  of  the  "oval"  pipe  on  the  upper 
end  as  shewn  on  the  line  A  B.  Space  the  semi-circles  in  both 
profiles  into  the  same  number  of  parts,  as  indicated,  and  at 
right  angles  to  I  5  and  A  B  respectively,  draw  lines  from  the 
various  points  2  to  4  and  10  to  6  until  they  cut  the  miter  lines 
i'  5'  and  6'  10'  as  shown.  Connect  by  lines  the  points  i'  and  10' 
and  5'  with  6',  which  completes  the  side  elevation.  The  half 
pattern  for  the  round  and  "oval"  pipes  will  be  laid  out  by  parallel 
lines  as  follows :  Extend  the  line  i  5  in  the  side  elevation  as 
shown  at  the  right  by  C  D,  upon  which  place  the  girth  of  the 
half  profile  of  the  round  pipe  as  shown.  From  the  small  figures 
erect  lines  at  right  angles  to  C  D,  and  intersect  same  by  lines 
drawn  parallel  to  C  D  from  the  various  points  i'  to  5'  on  the 
miter  line  in  elevation.  Trace  a  line  through  the  intersection 
thus  obtained;  then  will  i"  5"  5  i  be  the  half  pattern  to  which 
the  edges  must  be  allowed  for  seaming. 

In  precisely  the  same  manner  is  the  half  pattern  for  the  oval 
pipe  obtained.  B  A  in  elevation  is  extended  as  shown  by  /  E, 
upon  which  the  girth  of  the  half  profile  of  the  "oval"  pipe  is 
placed,  as  shown  by  similar  letters  and  figures  on  /  E.  The 
usual  measuring  lines  are  drawn  and  intersected  by  lines  drawn 
parallel  to  /  E  from  points  of  corresponding  number  on  the 
miter  line  6'  10'.  This  will  give  the  half  pattern  for  the  "oval" 
pipe,  to  which  edges  must  also  be  allowed  for  seaming  pur- 
poses. 

To  develop  the  middle  piece  of  the  offset,  connect  the  various 
points  10',  2',  9',  3',  etc.,  as  shown.  These  lines  will  then  repre- 
sent the  bases  of  sections  to  be  constructed  as  shown  in  the 
diagram  of  true  lengths,  whose  altitudes  will  equal  the  various 
hights  shown  by  corresponding  numbers  in  the  upper  and  lower 
semi-profiles  in  the  side  elevation.  Draw  any  horizontal  line 
as  F  G,  upon  which  place  off  the  lengths  of  the  several  lines 
shown  in  the  middle  section  in  the  elevation  as  shown  by  cor- 
responding numbers  on  F  G.  For  example,  to  find  the  true 
length  of  the  line  3'  9'  in  elevation,  take  this  distance  and  set  it 
off  on  F  G  as  shown  from  3'  to  9',  and  from  these  two  points 
erect  perpendiculars,  making  them  equal  respectively  to  the  hight 
of  lines  of  corresponding  number  in  the  half  profiles  of  the  side 


214 


FURNACE  FITTINGS 


/VOTE:    ALLOW 
TWO  MCH£5  FOX 
COLLAR  OAf  ttCr/WGULAK 


Fig.  163 — Placing  the  Semi- Profiles. 


FURNACE  FITTINGS  215 

elevation  as  measured  from  the  lines  I  5  and  A  B,  and  draw 
a  line  from  3  to  9  in  the  diagram,  which  is  the  desired  length. 
In  this  manner  all  of  the  true  lengths  are  obtained.  It  should 
be  understood  that  the  lines  i'  10'  and  5'  6'  in  elevation  show 
their  true  lengths,  but  these  two  lines  also  represent  the  base 
of  the  two  sections,  whose  altitudes  at  10'  and  6'  are  equal  to  A 
10  and  B  6  respectively,  the  true  lengths  of  these  two  invisible 
lines  being  indicated  by  i'  10  and  5'  6  in  the  diagram  of  true 
lengths. 


Fig.   164— Offset  Boot. 

It  will  not  be  necessary  to  develop  any  sections  on  the  miter 
lines  i'  5'  and  6'  10'  in  elevation  as  the  true  lengths  along  the 
miter  cuts  can  be  obtained  along  the  miter  cuts  in  patterns  of 
the  straight  pieces  respectively.  The  half  pattern  for  the  transi- 
tion piece  can  now  be  laid  out  as  follows :  First  draw  any  line 
as  A  i  in  the  pattern  equal  to  10'  i'  in  the  side  elevation.  With 
a  radius  equal  to  A  10  in  the  half  profile  and  A  in  the  pattern 
as  center,  describe  the  arc  near  10,  which  intersect  by  an  arc 
struck  from  i  of  the  pattern  as  center  and  the  true  length  i' 
10  as  radius.  With  i"  2"  in  the  half  pattern  of  lower  pipe  as 
radius  and  i  in  the  pattern  as  center,  describe  the  arc  2,  which 
intersect  by  an  arc  struck  from  10  as  center  and  10  2  in  dia- 
gram as  radius.  With  10'  9'  in  the  half  pattern  of  upper  pipe 
as  radius,  and  10  in  pattern  as  center,  describe  the  arc  near  9, 
which  intersect  by  an  arc  struck  from  2  of  pattern  as  center 
and  2  9  in  the  diagram  of  true  lengths  as  radius.  Proceed  in 
this  manner,  using  alternately  first  the  divisions  along  i"  5"  in 
the  pattern  for  the  lower  pipe,  with  the  proper  true  length  in 
the  diagram ;  then  the  divisions  along  A'  B'  in  the  pattern  for 
the  upper  pipe,  with  the  proper  true  length  in  the  diagram,  until 
all  dimensions  are  used.  A  line  traced  through  points  thus  ob- 
tained as  shown  by  A  B  5  i  completes  the  half  pattern,  to  which 
edges  must  be  allowed  for  seaming  and  joining.  The  method 
of  seaming  together  the  three  pieces  of  the  offset  is  similar  to 
that  shown  in  Fig.  127,  but  the  wall  pipe  slips  are  made  as  in- 
dicated by  S  in  Fig.  164. 


216 


FURNACE  FITTINGS 


/•    /'  +•  /o'  8' 7'  ?  J'<3'  6' 9' 

r/?V£  LENGTHS  Of  2/rt/LJG  A/Utf&£e£D  UA/£S  /M  5/£>£  £££ VAT/ON. 

a 


3          2  / 

ffALF  PATTERN  FOR  fiOUA/O  P/P£. 


7   A 


Fig.  165— Developing  Pattern  for  Offset  Boots. 


FURNACE  FITTINGS 


217 


Wall  Pipes  or  Risers 

The  wall  pipes  used  in  warm  air  heating  are  also  known  as 
risers,  stacks  or  flue  pipes.  They  are  made  with  single  and 
double  walls.  When  single  wall  pipes  are  used  they  should 
be  braced  on  the  inside  by  soldering  a  tin  brace  in  the  center  of 
the  pipe,  as  indicated  by  A  in  Fig.  166.  Where  this  is  not  done 


Air  ce// paper- 


Fig.  166 — How  the  Area  Is 
Decreased  in  Wall  Pipes. 


Fig.  167 — Method  of  Securing 
Air  Tight  Joints  in  Wall  Pipe. 


the  pressure  of  the  plaster  when  forced  through  the  lathing  de- 
creases the  area  of  the  pipe  as  indicated  by  the  dotted  lines  a 
The  braces  A  are  cut  24  mcn  wide  and  i  inch  longer  than  the 
width  of  the  pipe.  An  l/§  inch  hem  edge  is  turned  on  each  of 


dsoestos  <?//•  ce// 


Galvanized 

jheet  mete/ corner  dng/es 

Fig.  168 — Protecting  Asbestos  Covering. 

the  long  sides  of  the  brace,  leaving  it  >^  inch,  and  a  y2  inch 
edge  on  each  end,  which  is  turned  at  right  angles  to  be  used 
for  soldering  purposes  as  shown.  Care  must  be  taken  to  solder 
the  brace  in  edgewise,  so  as  not  to  interfere  with  the  flow  of 
the  air  or  decrease  the  capacity  of  the  pipe. 

Covering  Single  Wall  Pipes  with  Paper 

The  single  wall  pipes  can  be  covered  with  either  single  paper 
or  with  air  cell  or  corrugated  paper.  This  prevents  loss  of  heat 
in  the  walls,  the  paper  being  pasted  to  the  flue  pipes  as  follows : 


218  FURNACE  FITTINGS 

Cut  the  paper  about  %  inch  shorter  than  the  girth  required  to 
go  around  the  pipe.  To  apply  the  paper,  roll  it  up,  dip  in  water 
and  remove  immediately  and  apply  the  paste.  Put  the  paper 
on  the  pipe  while  it  is  soft  and  pliable.  Before  bringing  the  two 
edges  together  in  the  vertical  seam,  take  a  piece  of  flat,  stiff 
paper  about  3  inches  wide,  and  paste  over  one  edge  of  the  air 
cell  paper  as  shown  by  a  in  Fig.  167,  and  then  paste  down  on 
the  tin  pipe  at  b.  Now  bring  the  other  edge  of  the  air  cell  paper 
in  place  as  shown  by  c  and  paste  another  strip  of  stiff  paper 
over  the  joint  as  indicated  by  d.  This  secures  the  covering  along 
the  vertical  joints.  Do  the  same  with  the  horizontal  joints,  and 
always  have  the  corrugations  next  to  the  tin.  When  the  paper 
is  dry  a  good  solid  air  tight  covering  is  obtained, 

Double  Wall  Pipes 

Double  wall  pipes  have  the  advantage  over  the  single  wall  as 
the  walls  are  protected  from  crushing  by  means  of  perforated 
angles  and  corrugations  and  the  air  space  between  the  inner  and 
outer  pipes  prevents  loss  of  heat  in  the  partitions, 

Metal  Flues  in  Brick  Walls 

When  warm  air  pipes  are  run  up  in  brick  walls  as  the  mason's 
work  progresses,  galvanized  iron  is  generally  used,  covered  with 
asbestos  air  cell  covering.  The  corners  of  the  asbestos  covering 
is  usually  protected  from  injury  as  shown  in  Fig.  168,  in  which 
the  metal  pipe  is  first  covered  with  asbestos  air  cell  covering  .as 
previously  described,  then  the  corners  of  the  asbestos  covering 
are  protected  by  galvanized  sheet  iron  angles  3  inches  wide  on 
each  side,  which  prevents  the  paper  from  being  torn  or  damaged 
by  the  brick  work  or  studding.  These  galvanized  iron  angles 
are  held  in  position  by  thin  copper  wire  twisted  around  the  pipe 
at  intervals  of  about  12  inches  as  indicated  in  the  diagram. 

The  Various  Fittings  Used  in  Furnace  Piping 

Fig.  169  shows  twenty-six  styles  of  single  wall  furnace  fittings, 
including  every  conceivable  shape  usually  met  with  in  practice. 
The  same  style  of  fittings  can  also  be  obtained  for  double  wall 
pipe.  It  will  be  noticed  that  the  various  angles,  elbows,  offsets, 
tees,  register  boxes,  etc.,  are  so  constructed  that  no  development 
is  necessary  when  laying  out  the  patterns,  the  shapes  being 
pricked  direct  on  the  metal  and  edges  allowed  for  seaming  and 
grooving.  This  cut  should  be  referred  to  when  any  job  comes 
up,  as  from  these  twenty-six  styles  one  or  more  is  sure  to  sug- 
gest itself  for  practical  use. 


FURNACE  FITTINGS 


219 


Fig.  169— Twenty-six  Styles  of  Single  Wall  Furnace  Fittinga 


i— Angle  45°  Elbow.  8— Flat  Offset  Elbow. 

2 — Elbow  of  Three  Pieces.  9 — Two  Way  Tee. 

3— Elbow  90°.  10— Flat  Angle  45°. 

4— Regular  Elbow  90°  Round  Heel.  1 1— Through  Tee. 
5— Flat  Elbow  90°  Round  Heel.  12— Reduced  Tee. 
6— Offset  Elbow.  13— Flat  Two  Way  Tee. 

7— Flat  Elbow  90°  Octagonal  Heel.  14— Flat  Through  Tee. 


22o  FURNACE  FITTINGS 

15— Left  Compound  Tee  on  the  Flat.  21— Through  Register  Box. 
i6-Right  Compound  Tee  on  the  Flat.  22_Top     Register     BQX    and    Riser 

17 — Left     Compound    Tee     on     the  ^       ^     . 

Sharp.  23 — T°P  Register  Bex  Connected  to 

Combined.  Oval  Pipe. 

18 — Right    Compound    Tee    on    the  24 — Semi-circular  Register  Box. 

c-     1      -r        -n     •  .  r       25 — Double     Semi-circular     Register 

19 — Single    Top    Register    Box    for  „  .       _. 

Rectangular  Riser.  Boxes   for  Round  Rlsers- 

20— Double    Top    Register    Box    for  26 — Double    Corner    Register    Boxes 
Rectangular  Riser.  for  Round  Riser. 

Compound  Wall  Pipe  Offsets 

Compound  pipe  offsets  are  very  often  required  in  furnace 
piping.  When  the  partition  on  the  first  floor  runs  in  one  direc- 
tion, and  that  on  the  next  floor  runs  at  right  angles  to  the  lower 
one,  a  compound  or  double  offset  is  necessary  as  shown  in  Fig 
170,  where  the  two  wall  pipes  cross  one  another  at  right  angles, 
with  equal  projection  on  all  four  sides  as  shown.  In  an  offset 
of  this  kind  the  pattern  must  be  developed,  the  offset  usually 
being  made  up  in  four  pieces,  with  collar  attachment  and  the 
corners  double  seamed. 

The  method  of  developing  the  pattern  for  the  offset  is  so 
clearly  shown  in  Fig.  171  that  little  explanation  will  be  required. 
The  shape  of  the  two  pipes  is  clearly  shown  in  the  plan,  the 
vertical  night  of  the  offset  is  indicated  by  2  a  in  elevation,  and 
I  2  of  the  elevation  is  the  slant  hight  or  stretchout  to  be  used 
in  obtaining  the  pattern  as  shown  at  the  right.  Allow  for  a 
collar  at  either  end  to  make  connections  as  shown. 

Patterns  for  a  Double  Offset 

When  the  upper  heat  pipe  does  not  come  centrally  over  the 
lower  one,  but  offsets  to  one  side,  then  a  double  offset  is  required 
as  indicated  in  Fig.  172.  The  method  of  laying  out  the  pattern 
is  shown  in  Fig.  173,  which  method  can  be  applied  to  any  style 
of  offset,  regardless  of  what  shape  the  profiles  at  either  end 
may  be,  whether  similar  or  dissimilar,  or  whether  the  upper 
pipe  is  out  of  center  either  way  or  not,  providing,  however,  that 
the  sides  of  the  upper  pipe  run  parallel  to  those  of  the  lower 
pipe.  Referring  to  Fig.  173,  2,  5,  3,  5  in  plan  shows  the  shape 
of  the  lower  pipe  and  i,  6,  4,  6  the  shape  of  the  upper  pipe,  the 
two  being  similar  in  this  case.  The  amount  of  offset  is  equal  to 
3  i  in  plan,  the  narrow  side  of  the  upper  pipe  being  set  centrally 
to  the  wide  side  of  the  lower  one.  The  front  and  side  elevations 
are  projected  from  the  plan  as  shown,  being  careful  that  the 
vertical  hight  a  in  the  front  is  equal  to  a  of  the  side.  As  the 
flare  5  6  in  the  front  elevation  is  the  same  as  that  of  the  op- 
posite side,  then  will  the  pattern  for  one  side  answer  for  both. 


FURNACE  FITTINGS 


221 


In  the  side  elevation  the  flares   i   2  and  3  4  are  unequal ;  two 
patterns  will  therefore  be  required. 

To  obtain  the  pattern  for  the  side  shown  by  5  6  in  both  front 
elevation  and  plan,  proceed  as  follows:  At  right  angles  to  the 


Fig.  170 — Compound  Offset. 


72— Double   Offset. 


side  6  in  plan  draw  the  line  A  B,  upon  which  place  the  girth  or 
stretch-out  of  5  6  in  the  front  elevation  as  shown.  At  right  angles 
to  A  B,  through  points  5  and  6,  draw  the  usual  measuring  lines, 
and  intersect  same  from  sides  of  corresponding  number  in  plan 
as  shown,  which  will  give  the  pattern  for  the  sides  5  6.  Allow 
for  collars,  also  edges  for  seaming  at  the  corners.  For  the 


PLAN  Pattern  for  Sides. 

Fig.  171— Developing  the  Pattern  for  Compound  Offset. 

patterns  for  the  sides  I  2  and  3  4  in  the  side  elevation,  draw 
any  vertical  line  as  C  D  below  the  plan  as  shown,  upon  which 
place  the  girth  of  the  flares  i  2  and  3  4  in  the  side  elevation. 
Through  these  small  figures  on  C  D  draw  the  usual  measuring 
lines,  which  intersect  by  lines  projected  from  points  of  cor- 
responding numbers  in  plan,  all  as  shown  by  the  dotted  lines. 
Allow  collars,  also  edges  for  seaming  the  corners. 


222 


FURNACE  FITTINGS 


Pattern 
forS/des  /,<? 


Allow  Edges  on  & 
Patterns  for 
Double  Seaming. 


Fig.  173— Patterns  for  Double  Offset. 


FURNACE  FITTINGS 


223 


Fittings  for  Trunk  Line  Heating  Systems. 

Where  trunk  line  systems  of  heating  are  used,  special  fittings 
must  be  made  up,  which  are  usually  round  in  section.  Care, 
however,  must  be  taken  in  designing  the  branches,  tees  and  forks, 
that  the  main  supply  pipe  is  of  sufficient  area  to  feed  the  branches 
taken  therefrom,  as  will  be  explained  in  problems  to  follow. 


Fig.   175 — Short  Rule  for  Reducing  Joint. 


Five  types  of  trunk  line  fittings  will  be  shown.  Four  of  the 
types  will  require  triangulation  in  their  development,  but  one 
type  only  will  be  developed  in  detail,  showing  the  principles 
involved,  which  can  be  applied  to  the  balance  of  the  fittings  or 
any  other  size  or  angles  which  may  arise. 

Short  Rule  for  Reducing  Joint 

Fig.  174  shows  what  is  known  as  a  reducing  joint.  This  pat- 
tern can  be  developed  by  the  radial  line  system,  but  sometimes 
the  difference  between  the  large  and  small  diameters  is  so  little 
that  the  radius  would  become  so  long  as  to  make  it  impractical 
for  use.  To  overcome  this  a  short  rule  can  be  used  as  shown 
in  Fig.  175.  This  is  as  follows:  Draw  upon  the  sheet  metal  the 
outline  of  the  taper  joint  desired,  as  shown  by  a  b  c  d.  Now 
with  a  and  b  as  centers,  with  radius  less  than  a  b  draw  the  arcs 
e  f  and  e  f,  crossing  the  outlines  a  d  and  b  c  at  i  and  i  re- 
spectively. TTow  using  i  as  center  with  /  e  as  radius  intersect 
the  arc  at  /.  Do  the  same  in  obtaining  /'.  From  a  and  b  draw 
lines  through  /  and  /'  equal  in  length  to  a  b,  as  shown  by  a  b' 
and  b  b".  In  precisely  the  same  manner,  using  d  and  c  as  centers, 
draw  the  arcs  g  h  a-nd  g  ti  and  obtain  the  intersections  h  and  ti 


224 


FURNACE  FITTINGS 


by  using  k  and  k'  as  centers  with  radius  equal  to  k  g.  From  d 
and  c  draw  lines  through  h  and  h',  making  them  equal  in  length 
to  d  c,  as  indicated  by  d  c  and  c  c".  Draw  lines  from  b'  to  c' 
and  b"  to  c" .  Add  to  the  pattern  just  described  one  seventh  of 
the  shape  a  b  c  d}  as  shown  by  E  F.  This  is  obtained  by  divid- 
ing a  b  and  c  d  each  into  seven  parts  and  adding  one  of  these 
parts  as  indicated.  E.  F.  b"  c"  is  the  desired  pattern.  When 
cutting  out  the  pattern  a  curved  line  should  be  cut  along  the 
top  and  bottom,  carefully  allowing  edges  for  grooving  the  joint 
and  for  seaming  to  the  collars,  as  indicated  by  A  and  B  in  Fig. 
174- 

Determining  the  Unknown  Diameter  of  the  Main  Pipe 

Fig.   176  shows  a  view  of  an  equal  pronged   fork  fitting,  in 
a  trunk  line   system  of  heating.     When   laying  out   fittings   of 


Fig.  176 — Equal  Fork  in  Trunk  Line  Fittings. 

this  kind,  great  care  should  be  taken  in  regard  to  area,  as  before 
stated.  In  other  words  the  area  of  the  main  trunk  line  A  must 
equal  the  combined  areas  of  the  branches  B  and  C,  or  as  many 
branches  as  may  be  taken  from  the  main. 

To  avoid  computation  when  fitting  the  unknown  diameter  of 
the  main  pipe  A,  use  can  be  made  of  a  table  of  Circumferences 
and  Areas  of  Circles  to  be  found  in  chapter  19.  Assuming 
that  the  two  branches  are  each  8  inches  in  diameter,  follow  the 
column  of  diameters  in  the  table  to  8,  the  area  of  which  will 
be  found  to  be  50.26.  Double  this  for  the  two  similar  branches, 
making  a  total  of  100.52.  Now  following  the  column  of  areas 
in  the  table,  the  nearest  area  to  100.52  will  be  101.62,  which  rep- 
resents the  area  of  a  circle  nj^  in.  in  diameter,  as  shown  in  the 


FURNACE  FITTINGS 


225 


column  of  diameters.  The  main  pipe  A  must  be  n^j  in.,  which 
will  then  contain  the  combined  areas  of  the  two  8  in.  branches 
B  and  C 

Pattern  for  a  Fork  of  Equal  Prongs  in  Trunk  Line  System 

The  pattern  for  this  fitting  will  be  developed  by  triangulation, 
as  shown  in  detail  in  Fig.  177,  the  principles  of  which  can  also 
be  applied  to  the  other  problems  on  fittings,  which  will  follow 


Ztevatt'on  w'M  //<?//<  Pro f//es. 


ffaff  Potterfl-  A //or  fc/^es. 


Fig.  177 — Developing  the  Pattern  for  a  Two-Pronged  Fork. 


in  regular  order.  As  both  branches  are  to  have  the  same  di- 
ameter, the  pattern  for  the  one  will  answer  for  the  other.  First 
draw  the  elevation  of  the  fork  as  shown  by  i,  5,  6,  8",  5',  i',  10 
(in  practice,  but  one  half  of  elevation  will  be  required,  as  both 
prongs  are  similar).  On  the  line  i  5  in  elevation  draw  the  half- 
profile  A  ;  on  the  line  6  8",  the  half-profile  B,  and  draw  the  half- 
profile  on  the  line  8'  10  as  follows :  As  the  hight  of  the  joint  is 
equal  to  8'  10  and  the  half-depth  through  8'  equal  to  8'  8,  place 
this  distance  8'  8  at  right  angles  to  the  joint  line  8'  10,  as  shown 
by  8'  8",  and  draw  at  pleasure  a  graceful  quarter  of  an  elliptical 
figure  as  indicated  by  8"  9  10  or  C.  As  the  half-profile  B  and  C 
are  both  divided  in  two  equal  parts,  or  a  total  of  four,  then  divide 


226 


FURNACE  FITTINGS 


the  half-profile  A  into  four  spaces,  as  shown  from  I  to  5;  the 
half-profile  B  has  two  spaces,  as  shown  from  6  to  8,  and  the 
half-profile  C,  in  two  parts,  as  shown  from  8"  to  10.  From  these 
various  small  figures  at  right  angles  to  their  respective  base  lines, 
draw  line  intersecting  the  base  lines  at  2',  3',  4',  also  at  7'  and  9' 
Connect  opposite  points,  as  shown  by  the  dotted  lines.  These 
lines  then  represent  the  base  lines  of  sections  which  will  be  con- 
structed and  whose  altitudes  will  be  equal  to  the  various  heights 
in  the  half-profiles  A,  B  and  C.  Therefore  on  any  vertical  line, 
as  DE,  place  the  various  lengths  of  the  lines  in  elevation,  as 
shown.  From  the  points  on  DE  perpendiculars  are  erected 
whose  hights  are  equal  to  the  altitudes  in  the  various  half-sec- 
tions, and  the  points,  obtained  in  F,  are  then  connected  by  slant 
lines,  which  show  the  true  lengths,  all  as  shown  by  similar  num- 
bers. 


Fig.  178— Unequal  Fork  in  Trunk  Line  Fittings. 


The  half  pattern  shape  H  briefly  described  is  laid  out  as  fol- 
lows :  5  6  is  made  equal  to  5  6  in  elevation.    The  divisions  from 

5  to  i  are  obtained  from  the  half-section  A,  the  divisions  from 

6  to  8  from  the  half-section  B  and  the  divisions  from  8  to  10 
from  the  half-section  C.     The  length  of  the  dotted  lines  in  H 
are  obtained  from  the  true  lengths  in  F,  i-io  in  H  being  equal 
to  i-io  in  elevation.    Edges  must  be  allowed  for  seaming. 


FURNACE  FITTINGS 


227 


Determining   the   Unknown    Diameter  in  an   Unequal  Two 

Pronged  Fork 

Fig.  178  shows  an  unequal  two  pronged  fork  whose  branches 
A  and  B  are  7  and  10  inches  respectively  and  it  is  desired  to 
know  what  size  the  main  pipe  C  must  be.  This  is  found  with- 
out computation  by  using  the  table  previously  referred  to.  A 
7  in.  circle  has  an  area  of  38.48  sq.  in.,  and  a  10  in.  circle  an 
area  of  78.54,  making  a  total  of  117.02.  Now  the  nearest  num- 
ber to  117.02  in  the  column  of  areas  in  the  table  is  117.85,  which 
suggests  a  circle  12%  in.  in  diameter,  or  the  size  of  the  main 
pipe  C. 


Fig.  179 — Placing  the  Half-Profiles  in  an  Unequal  Pronged  Fork. 


Placing  the  Half  Profiles  Previous  to  Developing  the  Patterns 

In  Fig.  179  is  shown  how  the  half-profiles  are  to  be  placed 
when  developing  the  patterns  for  an  unequal  pronged  fork. 
Draw  the  outline  of  the  full  size  fork  as  shown  by  A  B  C  D  H 
E  F.  Bisect  A  B  and  obtain  the  point  J  and  draw  the  joint  line 
J.  H.  Place  semi-circles  on  the  lines  A  B,  C  D  and  E  F,  which 
represent  the  half-profiles.  At  right  angles  to  the  joint  line  H  J, 
from  the  center  J,  draw  the  line  J  a  equal  to  J  A,  as  shown,  and 
draw  a  quarter  elliptical  figure  shown  by  a  H.  The  profiles 
being  drawn,  they  are  spaced  and  the  patterns  developed  as  was 
shown  in  Fig.  177. 


228 


FURNACE  FITTINGS 


Three  Equal  Pronged  Fork 

In  Fig.  180  is  shown  a  fork  of  three  equal  size  prongs  in  a 
trunk  line  system,  so  placed  that  the  pattern  for  one  prong  can 


\\ 


Fig.  180 — Three  Equal  Pronged  Fork  in  Trunk  Line  System. 

be  used  for  all  three.  The  size  of  the  main  pipe  would  be  de- 
termined as  follows :  Following  the  column  of  areas  in  the  table, 
we  find  that  8  inch  circle  has  an  area  of  50.26  sq.  in.,  which 


Fig.  181— Method  of  Drawing  Three-Pronged  Fork  so  that  the  Pattern 
for  One  Will  Answer  for  All. 

multiplied  by  3  gives  a  total  of  150.78.  The  nearest  number 
to  150.78  in  the  column  of  areas  is  151.20  and  suggests  a  circle 
whose  diameter  is  13%  in.,  the  size  of  the  main  pipe. 


FURNACE  FITTINGS 


229 


Method  of  Drawing  Three  Pronged  Fork  so  that  the  Pattern 
for  One  Will  Answer  for  All  Three 

Fig.  181  shows  how  a  three  pronged  fork  is  drawn,  so  that 
the  angles  of  the  miter  joints  will  be  similar  and  the  pattern 
for  one  will  answer  for  all.  Having  determined  the  size  of 
the  main  pipe  as  a  b,  bisect  it,  and  obtain  c,  which  use  as  a  center 


Fig.  182 — Unequal  Three-Pronged  Fork  in  Trunk  Line  System. 

and  describe  the  semi-circle  a  d  b.  From  c  draw  the  perpen- 
dicular c  m.  Now  set  the  dividers  equal  to  c  a  and  starting 
from  a,  step  off  the  points  e  and  /.  Using  the  same  space,  step 
off  the  points  i  and  h,  starting  from  d.  Draw  the  joint  lines 
c  e  and  c  f  and  draw  lines  indefinitely  from  c  through  i  and  h 
shown  respectively  by  c  I  and  c  n.  Now  establish  the  height  of 
the  prong  as  c  o  and,  using  c  as  center  and  c  o  as  radius,  draw 
the  arc  r  s,  cutting  the  radial  lines  c  I  and  c  n  at  t  and  u.  On 
ascertaining  the  diameter  of  the  prong,  set  the  dividers  equal  to 
one-half  the  diameter  and  step  off  on  the  arc  r  s  on  either  side 
of  the  points  u  o  and  t,  the  divisions  shown  by  i  2,  3  4  and  5  6. 
Connect  these  points  by  lines  as  indicated,  which  makes  each  of 
the  three  prongs  similar.  As  the  two  halves  of  each  prong  are 
symmetrical,  it  is  only  necessary  to  develop  the  pattern  for  one 
half,  as  indicated  by  a  6  t  c,  placing  the  quadrants  for  that  pur- 
pose as  follows :  With  c  as  center  and  c  a  as  radius,  draw  the 
quadrant  shown  shaded,  at  B.  With  t  as  center  and  t  6  as  radius, 
draw  the  quadrant  shown  by  A.  Now  divide  both  quadrants  in 
equal  number  of  spaces  and  proceed  to  draw  the  base  lines  and 
develop  the  true  lengths  and  patterns  as  previously  described. 


230 


FURNACE  FITTINGS 


Unequal  Three  Pronged  Fork 


Fig.  182  shows  an  unequal  three  pronged  fork,  each  diameter 
being  different,  and  each  fork  leading  at  a  different  angle.  In 
this  case  the  diameters  are  6,  8  and  10  in.  and  represent  areas 
of  28.27,  50.26  and  78.54,  making  a  total  area  of  157.07.  The 
nearest  area  to  this  number  is  159.48  and  represents  the  area 
of  a  14^4  in-  pipe,  the  desired  dimensions  as  shown. 


Fig.  183 — Finding  True  Sections  and  Placing  Profiles. 


Finding  the  True   Sections  and  Placing  the   Profiles  in  an 
Unequal  Three  Pronged  Fork 

While  the  method  of  developing  the  patterns  for  an  unequal 
three  pronged  fork  is  similar  to  those  already  described,  care 
must  be  taken  to  draw  and  place  the  profiles  properly,  as  is 
shown  in  Fig.  183.  In  this  figure  abcdefghij  shows  the 
desired  outline  of  the  fork  and  that  it  has  the  desired  angles  and 
proper  dimensions  and  diameters.  On  the  line  a  j  draw  the  semi- 
circle D,  and  on  the  lines  b  c,  e  f  and  h  i  the  half-profiles  A,  B 


FURNACE  FITTINGS 


231 


and  C  respectively.  Now  at  right  angles  to  the  joint  lines  d  I 
and  /  g  draw  the  lines  /  a  and  /  /  equal  respectively  to  /  a  and  /  /. 
Now  from  the  intersections  a  and  /  draw  the  quarter  elliptical 
figures  indicated  by  a  d  and  /  g,  or  E  and  F.  So  that  the  method 
of  placing  the  half-profiles  may  not  confuse  the  reader,  the 
prongs  have  been  numbered  i,  2  and  3  and  have  been  duplicated 
as  indicated  by  ia,  2a  and  3a,  on  which  the  profiles  are  placed 
in  their  proper  positions,  being  duplicates  of  similar  lettered  pro- 
files in  i,  2  and  3.  A  little  study  will  make  this  clear,  after 
which  the  spacing  of  the  profiles  and  obtaining  the  true  lengths 
and  the  patterns  are  in  order. 

Finding  True  Angles  in  Cold  Air  Duct  Elbows 

It  is  often  the  case  that  special  elbows  must  be  prepared  and 
the  true  angle  be  found,  especially  where  they  pitch  in  both  direc- 
tions, as  indicated  in  Fig.  184,  where  a  plan  and  elevation  of  a 


Cold  SAT 


Fig.  184 — Example  in  Cold  Air  Duct  Elbows  in  Furnace  Work. 

round  cold  air  duct  is  shown.  In  this  case  true  angles  must  be 
found,  as  none  of  the  angles  in  either  plan  or  elevation  show 
their  true  pitch.  The  height  of  the  elbow  from  the  cellar  line 
is  indicated  by  A,  its  projection  by  B  in  plan,  and  it  leans  away 
from  the  reader  as  much  as  is  indicated  by  C.  The  method  of 
finding  the  true  length  of  the  middle  pipe,  also  the  true  angles 
of  the  two  elbows,  is  indicated  in  the  detail  drawing  in  Fig.  185, 
in  which  the  heavy  dotted  lines  show  the  center  line  of  the 
pipe,  all  that  is  necessary.  A  B  C  D  represents  the  center  of 


232  FURNACE  FITTINGS 

the  pipe  in  plan,  its  lean  away  from  the  reader  being  shown  by 
a  D.  The  same  center  line  is  shown  in  elevation  by  A1  B1  C1 
D1,  the  rise  being  indicated  by  b  C1  and  the  projection  by  B1  b, 
The  first  step  in  finding  the  true  length  of  B  C  in  plan  or  B1  C1 
in  elevation  is  to  place  the  height  of  b  C1  at  right  angles  to  B  C 
in  plan,  as  indicated  by  C  C2,  and  draw  a  line  from  C2  to  B, 
the  desired  length.  As  A  B  and  C  D  in  plan  and  A1  B1  and 
C1  D1  in  elevation  lie  in  horizontal  planes,  they  then  show  their 
true  lengths.  Now  to  find  the  true  angle  of  A  B  C  in  plan,  draw 
a  line  from  A  to  C,  take  this  distance  and  place  it  on  any  line 
as  A  C  in  diagram  X  and  at  right  angles  to  A  C  draw  C  C1 
equal  to  b  C1  in  elevation.  Draw  a  line  from  C1  to  A,  which  is 
the  true  length  of  C  A  in  plan.  Now  with  the  true  length  C2  B 
in  plan  as  radius  and  C1  in  diagram  X  as  center,  draw  the  arc  E, 
which  intersect  by  an  arc  struck  from  A  as  center  and  A  B  in 
plan  or  A1  B1  in  elevation  as  radius.  The  dotted  line  drawn 
from  C1  to  E  to  A  shows  the  true  angle  for  the  elbows  for 
A1  B1  C1  in  elevation  or  A  B  C  in  plan. 

The  true  angle  on  B  C  D  in  plan  is  obtained  in  a  similar 
manner.  The  distance  from  B  to  D  in  plan  is  placed  as  shown 
by  B  D  in  diagram  Y,  perpendicular  to  which  D  C1  is  erected 
equal  to  b  C1  in  elevation.  Then  with  C  D  and  B  C2  in  plan 
as  radii,  and  using  C1  and  B  respectively  in  diagram  Y  as  cen- 
ters, arcs  are  intersected  at  H,  thus  forming  the  desired  true 
angle  B  H  C1. 

Method  Employed  when  Developing  the  Elbow  Patterns 

After  the  true  angles  have  been  found  the  patterns  are  laid 
out  similarly  to  other  elbow  work.  For  example,  the  angle 
A  E  C1  is  bisected,  thus  obtaining  the  line  c  d  and  the  profile  F 
of  the  pipe  placed  as  shown,  with  the  center  point  a  placed  upon 
the  line  E  C1.  The  profile  is  now  divided  into  equal  spaces  and 
the  pattern  obtained  as  usual.  Of  course  it  is  understood  that 
the  arms  of  the  elbows  are  usually  made  about  6  in.  long  at 
the  throat,  making  a  slip  joint  for  the  center  pipe,  no  matter 
how  short  this  may  be.  This  method  obviates  the  labor  of  find- 
ing the  amount  of  twist  between  the  two  elbows  B1  and  C1  in 
elevation. 

True  Angles  in  Warm  Air  Elbows 

When  true  angles  are  required  in  warm  air  elbows  the  same 
principles  are  employed.  Fig.  186  gives  an  example  of  what 
is  likely  to  arise  in  practice.  This  shows  a  pipe  line  connecting 
to  the  first  floor  register.  In  elevation  the  rise  is  equal  to  a 
and  b  respectively,  while  in  plan  the  pipe  leans  toward  the  reader 


FURNACE  FITTINGS 


233 


^^X"^         S  Vay ratn  Y 


'    rrue  Jnffe  o*  0-C-O  //?  fVan. 


A     rrue  Any/e  on  A-B-C  in  P/an.  C 


f/evet/on 


Pldfl* 


Fig.  185— Finding  True  Angles  of  Circular  Cold  Air  Ductv 


234 


FURNACE  FITTINGS 


as  much  as  indicated  by  c.     This  problem  has  been  worked  out 
in  Fig.  187,  in  which  A  B  C  D  shows  the  rise  of  the  center  line 


Fig.  186 — Example  in  Finding  True  Angles  in  Warm  Air  Elbows. 

of  the  pipe  in  elevation.     The  first  run  of  pipe  A  B  has  a  rise 
equal  to  a  B,  while  the  second  run  B  C  has  a  rise  equal  to  b  C, 

<•' 


Fig.  187 — Finding  the  True  Angles. 

the  pipe  C  D  being  made  to  suit  the  connection  to  the  regis- 
ter box. 


FURNACE  FITTINGS 


235 


A1  B1  C*  in  plan  shows  similar  center  line  of  pipe,  leaning 
toward  the  reader  a  distance  equal  to  d  C1.  The  center  line  of 
the  pipe  C  D  in  elevation  is  indicated  in  plan  by  the  dot  C1  D1. 
Now  to  find  the  true  length  of  the  run  B  C  and  the  true  angle 
of  B  C  D  in  elevation,  proceed  as  follows :  Take  the  hight  from  b 
to  C  to  D  in  elevation  and  place  it  at  right  angles  to  B1  C1  in 
plan  as  shown  respectively  by  C1  to  C2  to  D2  and  draw  the  lines 


Fig.  1 88 — Finding  True  Angles  with  Line  and  Bevel. 


from  B1  to  C2  to  D2,  which  will  give  the  true  length  as  well  as 
the  true  angle  of  B  C  and  B  C  D  in  elevation.  As  A1  B1  in 
plan  lies  in  a  horizontal  plane,  then  A  B  in  elevation  shows  its 
true  length.  To  obtain  the  true  angle  of  A  B  C  in  elevation  or 
A1  B1  C1  in  plan,  take  the  distance  of  A1  C1  and  place  it  in  X 
as  shown.  From  C1  erect  the  perpendicular  C1  C3  equal  to  the 
combined  nights  of  the  two  runs  in  elevation,  as  c  b  C.  Now 
with  radii  equal  to  A  B  in  elevation  and  B1  C2  in  plan  and  using 
A1  and  C3  in  X  as  centers,  intersect  arcs  at  B2.  A1  B2  C3  then 
becomes  the  true  angle  desired.  The  patterns  are  developed  in 
exactly  the  same  way  as  before  described. 

Finding  True  Angles  with  Line  and  Bevel 

A  practical  way  to  find  the  true  angles  without  any  drawing 
is  to  do  it  directly  at  the  job,  using  only  a  line  and  bevel,  and  is 
shown  in  connection  with  Fig.  188.  The  furnace  and  cold  air 
inlet  c  being  in  position,  nail  a  slat  on  the  inlet  sill,  as  far  as  the 
pipe  is  to  project  from  the  wall,  as  shown ;  also  put  a  nail  in  the 
concrete  floor  near  the  furnace  where  desired.  Now  drive  a 


236  FURNACE  FITTINGS 

nail  at  the  end  of  the  slat  and  draw  a  line  taut  from  b  to  a.  It 
is  now  an  easy  matter  to  place  a  bevel  at  a  and  b,  then  take  di- 
mensions at  the  inside  corners  of  the  bevel  legs,  after  which  the 
bevel  can  be  closed,  and  then  again  opened  when  the  patterns 
are  laid  out  in  the  shop.  Before  removing  the  line,  the  true  length 
from  a  to  b  can  be  measured. 


237 


CHAPTER  XIX 
RULES,  TABLES  AND  INFORMATION 

The  following  pages  contain  rules,  tables  and  useful  in- 
formation of  value  to  the  sheet  metal  worker  and  furnace 
man. 

This  information  has  been  collected  from  so  many  sources 
that  it  is  next  to  impossible  to  give  credit  to  the  authors  or 
compilers  of  the  data  and  tables  published. 

The  author  of  this  book  desires  to  acknowledge  his  obliga- 
tion to  each  of  those  who  are  in  any  way  responsible  for  the 
data  published,  believing  that  no  objection  will  be  made  to 
the  use  of  the  information  for  the  benefit  of  the  trade. 


238 


WEIGHTS  AND   GAUGES  OF   SHEET   METALS 


Weights  of  Steel 


Approximate 

Approximate 

Weight 

1    "          ~ 

No. 
of  Gauge 

thickness  in 
fractions  of 
an  inch 

Thickness  ir. 
decimal  parts  of 
an  inch 

pet  square  foot 
in  pounds 
Avoirdupois 

per  square  foot 
in  pounds 
Avoirdupois 

Birming- 
ham 

No 

jof  Gauge  i 

U.S.  Standard 

U.  S.  Standard 

Iron 

Steel 

ooooood 

L-2 

•5 

2O.OO 

20.4 

7* 

OOOOOO 

15-32 

.46875 

18-75 

19    12$ 

.... 

6' 

OOOOO 

7-16 

•4375 

17.50 

17.85 

.... 

5° 

oooo 

13-32 

.40625 

16.25 

16-575 

•  454 

4' 

000 

3-8 

•375 

I  5. 

15.30 

•  425 

3j 

00 

n  -32 

•34375 

13-75 

14.025 

•  380 

o 

5-16 

•3125 

12.50 

12.75 

•  340 

o 

I 

0-32 

.28125 

11.25 

H.475 

-.300 

j 

2 

17-64 

.265625 

10.625 

»o  8375 

.284 

2 

3 

1-4 

.25 

10. 

1O  2 

-259 

3 

4 

15-64 

•234375 

9-375 

9.5625 

4 

I 

7-32 
18-64 

.21875 
.203125 

8.75 
8.125 

8.925 
8.2875 

.220 
.203 

I 

7 

3-16 

•  1875 

7-5 

7.65 

.180 

7 

8 

11-64 

.171875 

6.875 

7.0125 

.165 

fc 

9 

5"~32 

.15625 

6.25 

6-375 

,148 

Q 

10 

9-64, 

.  140625 

5.625 

5-7375 

•  »34 

10 

II 

1-8 

.125 

5- 

5  I 

.120 

ir 

12 

7-641 

.109375 

4-375 

4.4625 

.109 

12 

13 
14 

3-32 
5-64 

.09^75 
.078125 

3-75 

3.825 
3-1875 

.095 
.083 

13 
*4 

15 

9-128 

.0703125 

2^8125 

2.86875' 

.072 

15 

16 

1-16 

.0625 

2-5 

2-55 

16 

17 

9-160 

.05625 

2.25 

2.295 

'.058 

17 

18 

1-20 

.05 

2. 

2.04 

.049 

18 

19 

7-IOO 

.04375 

•75 

1.785 

.042 

19 

20 

3-80 

•0375 

.50 

1-53 

•035 

20 

21 

II-32O 

•034375 

•375 

1.4025 

.032 

21 

22 

1-32 

.03125 

•25 

1-275 

.028 

22 

23 

9-320 

.028125 

.125 

1-1475. 

.025 

23 

24 

.    1-40 

.025 

. 

1.02 

.022 

'24 

3 

7-320 
3-160 

.021875 
.01875 

•875 
•     -75 

.8925 
.765 

.020 
.018 

27 

1  1  -640 

.0171875 

.6875 

.70125 

.Ol6 

27 

28 

1-64 

.015625 

.625 

.6375   ' 

.014 

28 

29 

9-640 

.0140625 

.5625 

•57375 

.013 

29 

30 

1-80 

.0125 

•5 

.012 

30 

3* 

7-640 

.0109375 

.4375 

.44625 

.OIO 

3* 

32 

13-1280 

.01015625 

.40625 

-414375  ' 

.OO9 

3* 

33 

3-320 

.009375 

•375    , 

.3825 

.008 

33 

31 

11-1280 

.00859375 

•34375 

.350625 

.007 

34 

1 

5-640 
9-1280 

.0078125 
.00703125 

.3125 

.28125 

.3'875 
.286875 

.005 
.O04 

17-2560 
1-160 

.006640625 
.00625 

.  2/55625 

;25 

.2709375 
•255 

.... 

I 

"to 

JV 

" 

WEIGHTS  AND  GAUGES  OF  SHEET  METALS 


239 


GAUGES  AND  WEIGHTS  OF  BLACK  SHEETS. 


No.  of 
Gauge   or 
Thickness 
of  Sheet 

Approximate  Thickness  in  Inches. 

Weight  per  Square  Foot  in  Pounds 

U.  S.  Standard, 
adopted  by  U.  S. 
Government 
July  1,  1893 

Birming- 
ham 
Wire 
Gauge 

American 
or 
Brown  & 
Sharpe's 
Decimals 

U.  S. 
Standard 

Birming- 
ham 
Wire 
Gauge 

American 
or 
Brown  & 

Sharpe's 

fractions         Decimals     I"  Decimals 

Steel 

Steel 

Steel 

5-0's 

7-16 

437 

17  50 

0000 

13-32 

.406 

.454 

.46 

16.25 

IS  AQ 

18.77 

000 

3-8 

.375 

.425 

.409 

15. 

17.28 

16.71 

00 

11-32 

.343 

.38 

.364 

13.76 

15.45 

14.88 

0 

5-16 

.312 

.34 

.324 

12.50 

13.82 

13.26 

1 

9-32 

.281 

.30 

.289 

11.25 

12.20 

11.80 

2 

17-64 

.265 

.284 

.257 

10.625 

11.55 

10.51 

3 

1-4 

.25 

.259 

.229 

10. 

10.53 

9.36 

4 

15-64 

.234 

.238 

.204 

9.375 

9.68 

8.34 

5 

7-32 

.218 

.22 

.181 

8.75 

8.95 

7.42 

6 

13-64 

.203 

.203 

.162 

8.125 

8.25 

6.61 

7 

3-16 

.187 

.18 

.144 

7.5 

7.32 

5.89 

8 

11-64 

.171 

.165 

.128 

6.875 

6.71 

5.24 

9 

5-32 

.156 

.148 

.114 

6.25 

6.02 

4.67 

10 

9-64 

.140 

.134 

.101 

5.625 

5.45 

4.16 

11 

1-8 

.125 

.12 

.09 

5. 

4.88 

3.70 

12 

7-64 

.109 

.109 

.08 

4.375 

4.43 

3.30 

13 

3-32 

.093 

.095 

.072 

3.75 

3.86 

2.94 

14 

5-64 

.078 

.083 

064 

3.125 

3.37 

2.62 

15 

9-128 

.070 

.072 

.057 

2.8125 

2.93 

2.33 

16 

1-16 

.062 

.065 

.05 

2.5 

2.64 

2.07 

17 

9-160 

.056 

.058 

.045 

2.25 

2.36 

1.85 

18 

1-20 

.05 

.049 

.04 

2. 

1.99 

1.64 

19 

7-160 

.043 

.042 

.035 

1.75 

1.71 

1.46 

20 

3-80 

.037 

.035 

.032 

.50 

1.42 

1.31 

21 

11-320 

.034 

.032 

.028 

.375 

1.30 

1.16. 

22 

1-32 

.031 

.028 

.025 

.25 

1.14 

1.03 

23 

9-320 

.028 

.025 

.022 

.125 

1.02 

.922 

24 

1-40 

.025 

.022 

.020 

.895 

.82 

25 

7-320 

.021 

.02 

.017 

.'875 

.813 

.73 

26 

3-160 

.018 

.018 

.015 

.75 

.732 

.649 

27 

11-640 

.017 

.016 

.Q14 

.6875 

.651 

.579 

28 

1-64 

.015 

.014 

.012 

.625 

.569 

.514 

29 

-9-640 

.014 

.013 

.011 

.5625 

.461 

30 

1-80 

.012 

.012 

.01 

.5 

.408 

31 

7-640 

.010 

.01 

.008 

.4375 

.363 

32 

13-1280 

.010 

.009 

.008 

.4062 

.326 

34 

11-1280 

.008 

,007 

.006 

.3437 

.257 

36 

9-1280 

.007 

.004 



;2812 

... 



The  U.  S.  Standard  Gauge  is  the  one  commonly  used  in  the  United  States. 

In  figuring  weights  of  Steel  Plates  add  to  above  the  allowances  for  overweight, 
adopted  by  Association  American  Steel  Manufacturers. 


240 


WEIGHTS  AND  GAUGES  OF  SHEET  METALS 


GALVANIZED     SHEETS. 


GAUGES,  WEIGHTS  AND  NUMBER  SHEETS  IN  BUNDLE 


Size 
of 

wt, 

Weight 
of 

Number 
of 

Size 

of 

Weight 
of 

Weight 

Size 
of 

wp. 

Weieht 
of 

Number 
of 

Sheet 

Sheet 

Bandlo 

Sheets 

Sheet 

Sheet 

Bundle 

Sheet 

Sheet 

Bundle 

Sheets 

No.  14  (3.28  Ibs.  sq.  ft.)  (   No.  16  (2.65  Ibs.  sq.  ft.)  ||  No.  18  (2.15  Ibs.  sq.  ft.) 

24x72 

39.37 

157 

4 

24x72 

31.  87 

159 

5 

24x72 

25.87 

155 

6 

26x72 

42.65 

170 

4 

26x72 

34.5 

138 

4 

26x72 

28. 

140 

5 

28x72 

45.9 

138 

3 

28x72 

37.18 

148 

4 

28x72 

30.18 

150 

5 

30x72 

49.2 

147 

3 

30x72 

39.84 

159 

4 

30x72 

32.34 

161 

5 

36x72 

59. 

177 

3 

36x72 

47.8 

143 

3 

36x72 

38.8 

155 

4 

24x84 

459 

137 

3 

24x84 

37.18 

149 

4 

24x84 

30.18 

151 

5 

26x84 

49.74 

149 

3 

26x84 

40.2 

161 

4 

26x84 

32.68 

163 

5 

28x84 

53.58 

161 

3 

28x84 

43.37 

173 

4 

28x84 

35.2 

140 

4 

30x84 

57.4, 

172 

3 

30x84 

46.48 

139 

3 

30x84 

37.7 

151 

4 

36x84 

68.9 

137 

2 

36x84 

55.78 

167 

3 

36x84 

45.28 

135 

3 

24x96 

52.5 

157 

3 

24x96 

42.5 

170 

4 

24x96 

34.5 

138 

4 

26x96 

56.8 

170 

3 

26x96 

46. 

138 

3 

26x96 

37.36 

149 

4 

28x96 

61.2 

183 

3 

28x96 

49.56 

149 

3 

28x96 

40.23 

161 

4 

30x96 

65.6 

131 

2 

30x96 

53.12 

159 

3 

30x96 

43.12 

172 

4 

36x96 

78.75 

157 

2 

36x96 

63.75 

127 

2 

36x96 

51.75 

155 

3 

No.  20  (1.65  Ibs.  sq.  ft.) 

No.  22  (1.40  Ibs.  sq.ft.) 

No.  24  (1.15  Ibs.  sq.  ft.) 

24x72 

19.87 

159 

8 

24x72 

16.87 

151 

9 

24x72 

13.87 

152 

11 

26x72 

21.53 

151 

7 

26x72 

18.28 

146 

8 

26x72 

15.03 

150 

10 

28x72 

23.18 

162 

7 

28x72 

19.68 

157 

8 

28x72 

16.18 

145 

9 

30x72 

2484 

149 

6 

30x72 

21. 

147 

7 

30x72 

17.34 

156 

9 

36x72 

29.8 

149 

5 

36x72 

25.3 

152 

6 

36x72 

20.8 

145 

7 

24X84 

23.18 

162 

7 

24x84 

19.68 

157 

8 

24x84 

16.18 

145 

9 

26x84 

25.1 

150 

6 

26x84 

21.3 

149 

7 

26x84 

17.52 

140 

8 

28x84 

27. 

135 

5 

28x84 

22.96 

160   7 

28x84 

18.88 

151 

8 

30x84 

28.97 

145 

5 

30x84 

24.6 

148 

6 

30x84 

20.23 

141 

7 

36x84 

34.78 

139 

4 

36x84 

29.53 

147 

5 

36x84 

24.28 

145 

6 

24x96 

26.5 

159 

6 

24x96 

22.5 

157 

7 

24x96 

18.5 

148 

8 

26x96 

28.7 

143 

5 

26x96 

24.37 

146 

6 

26x96 

20. 

160 

8 

28x96 

30.9 

154 

5 

28x96 

26.24 

157 

6 

28x96 

21.57 

151 

7 

30x96 

33.12 

166 

5 

30x96 

28.12 

140 

5 

30x96 

23.12 

162 

7 

36x96 

39.75 

159 

4 

36x96 

33.75 

169 

5 

36x96 

27.75 

166 

6 

No.  26  (.906  Ibs.  sq.  ft.) 

No.  27  (.843  Ibs  sq.  ft.) 

No.  28  (.781  Ibs.  sq.  ft.) 

J  24x72 

10.87 

152 

14 

24x72 

10.12 

151 

15 

24x72 

9.37 

149 

16 

26x72 

11.78 

153 

13 

26x72 

10.96 

153 

14 

26x72 

10.15 

152 

15 

28x72 

12.68 

152 

12 

28x72 

11.81 

153 

13 

28x72 

10.93 

153 

14 

30x72 

13.57 

149 

11 

30x72 

12.65 

151 

12 

30x72 

11.71 

152 

13 

36x72 

16.3 

146 

9 

36x72 

15.18 

151 

10 

36x72 

14.06 

155 

11 

24x84 

12.68 

152 

12 

24x84 

11.81 

153 

13 

24x84 

10.93 

153 

14 

26x84 

13.73 

151 

11 

26x84 

12.78 

153 

12 

26x84 

11.84 

153 

13 

28x84 

14.79 

148 

10 

28x84 

13.77 

15,1 

11 

28x84 

12.75 

153 

12 

30x84 

15.85 

152 

10 

30x84 

14.76 

147 

10 

30x84 

13.67 

150 

11 

36x84 

19.03 

154 

8 

36x84 

17.7 

159 

9 

36x84 

16.4 

148 

9 

24x96 

14.5 

145 

10 

24x96 

13.5 

148 

11 

24x96 

12.5. 

150 

12 

26x96 

15.7 

157 

10 

26x96 

14.62 

146 

10 

26x96 

13.53 

148 

11 

28x96 

16.9 

152 

9 

28x96 

15.74 

157 

10 

28x96 

14.57 

146 

10 

30x96 

18.12 

145 

8 

30x96 

16.87 

152 

9 

30x96 

15.62 

156 

10 

36x96 

21.75 

152 

7 

36x96 

20.25 

162 

8 

36x96 

18.75 

150 

8 

WEIGHTS  AND  GAUGES  OF  SHEET  METALS 


241 


SHEET    COPPER 

TABLE  OF  WEIGHT  PER  SQUARE  FOOT,  AND  THICKNESS,  PER  STUBS' 

WIRE  GAUGE. 


Stubs' 
Guage 
(nearest 
No.) 

Thickness 
in  decimal 
parts  of 
1  inch 

Ounce 
per 
square 
foot 

14x48 

ibs. 

24x96 
Ibs. 

30x60 

Ibs. 

24x72 
Jbs. 

30x96 
tba. 

36x96 
tbs. 

30x120 
Ibs. 

35 

.00537 

4 

1.16 

4 

3.12 

3. 

5. 

6. 

6.24 

33 

.00806 

6 

1.F5 

6 

4.68 

4.50 

7  50 

9. 

9.36 

31 

.0107 

8 

2.33 

8 

6.25 

6. 

10. 

12. 

12.50 

29 

.0134 

10 

2.91 

10 

7.81 

7.50 

12.50 

15. 

15.62 

27 

.0161 

12 

3.50 

12 

9.37 

9. 

15. 

18. 

18.74 

26 

.0188 

14 

4.08 

14 

10.93 

10.50 

17.50 

21. 

21.86 

24 

.0215 

16 

4.66 

16 

12.50 

12. 

20. 

24. 

25. 

23 

.0242 

18 

5.25 

18 

14.06 

13.50 

22.50 

27. 

28.12 

22 

.0269 

20 

5.83 

20 

15.62 

15. 

25. 

30. 

31.24 

21 

.0322 

24 

7. 

24 

18.75 

18. 

30. 

36. 

37.50 

19 

.0430 

32 

9.33 

32 

25. 

12. 

40. 

48. 

50. 

18 

.0538 

40 

11.66 

40 

31.25 

30. 

50. 

60. 

62.50 

16 

.0645 

48 

14. 

48 

37.50 

36. 

60. 

72. 

75. 

15 

.0754 

56 

16.33 

56 

43.75 

42. 

70. 

S4. 

87.50 

14 

.0860 

64 

18.66 

64 

50. 

48. 

80. 

96. 

100. 

13 

.095 

70 

70 

55. 

52.50 

87.50 

105. 

110. 

12 

.109 

81 

81 

63. 

61. 

101.25 

121.50 

126. 

11 

.120 

89 

89 

70. 

67. 

111.50 

133.50 

140. 

10 

.134 

100 

.  .  . 

100 

78. 

75. 

125. 

150. 

156. 

9 

.148 

110 

110 

86. 

82.50 

137.50 

165. 

172. 

8 

.165 

123 

123 

96. 

92. 

153.75 

184.50 

192. 

7 

.180 

134 

134 

105. 

100.50 

167.50 

201. 

210. 

6 

.203 

151 

. 

151 

118. 

113.50 

188.75 

226.50 

236. 

5 

.220 

164 

164 

128. 

123. 

205. 

246. 

256. 

4 

.238 

177 

177 

138. 

133. 

221.25 

265.50 

276. 

3 

.259 

193 

193 

151. 

144. 

241.25 

289.50 

302. 

2 

.284 

211 

. 

211 

165. 

158. 

263.75 

316.50 

330. 

1 

.300 

223 

223 

174. 

168. 

278.75 

334.50 

348. 

0 

.340 

253 

253 

198. 

190. 

316.25 

379.50 

396., 

These  weights  are  theoretically  correct,  but  variations  must  be  expected  in 
practice. 


242  WEIGHTS  AND  GAUGES  OF  SHEET  METALS 

APPROXIMATE  WEIGHT  OF  SHEET  ZINC. 


Zinc 
Numbers 

Weight  per 
Square  Foot, 

Thickness  in 
decimals  of  an,      1 
Inch. 

American  or 
U.  S.  Gauge. 

Average  weight 
per   sheet   36x84 
Pounds. 

5 

.37 

.010  (Tta) 

32 

7.77 

6 

.45 

.012 

30 

9.45 

7 

.52 

.014 

.29 

10.92 

8 

.60 

.016 

28 

12.90 

9 

.67 

.018 

26 

14.32 

10 

.75 

.020  to) 

25 

17J6 

11 

.90 

.024 

24 

20.00 

12 

.05 

.028 

23 

22.84 

13 

.20 

.032 

22 

25.20 

14 

.35 

.036 

21 

28.52 

15 

.50 

.040  (2'5) 

20 

31.50 

16 

.68 

.045 

19 

35.28 

17 

.87 

.050 

18 

39.27 

18 

2.06 

.055 

17 

45.55 

19 

2.25 

-060  GV) 

16' 

47.25 

20 

2.62 

.070 

15 

55,02 

21 

3.00 

.080 

14 

63.00 

22 

3.37 

.090 

131 

70.77 

23 

3.75 

.100  to) 

12 

78.75 

24 

4.70 

.'125  (H) 

11 

98.70 

25 

9.40 

.250  (K) 

3 

197.40 

26 

14.10 

.375  (y8) 

000 

296.10 

27 

18.80 

.500 

0000000 

28 

37.60 

1.000 

WEIGHTS  OF  GALVANIZED  PIPE  AND 
ELBOWS 

SMOKE  PIPE— JOINTS  26*  LONG. 

24  GAUGE 

7"  Diam.  Lock  Seam  4  Ib.  8  oz. 
8*  Diam.  Lock  Seam  5  Ib.  2  oz. 
9*  Diam.  Lock  Seam  6  Ib.  2  o*. 

26  GAUGE 

7*  Diam.  Lock  Seam  3  Ib.  9  o*, 
8*  Diam.  Lock  Seam  .  4  Ib.  3  o». 


ELBOWS— 4  PIECE. 
24  GAUGE 


7*  Diam. 
8*  Diam 
9*  Diam. 


V  Diam. 
8*  Diam. 
9*  Diam. 


26  GAUGE 


1  Ib.  11  oz. 

2  Ib.  9  oz 
.3  Ib.  8  oz. 


1  Ib.  8  oz. 

1  Ib:  14  o» 

2  Ib.  6  09. 


WEIGHTS  AND  GAUGES  OF  SHEET  METALS 


243 


NET  WEIGHT  PER  BOX  TIN  PLATES. 


Basis,  10x14,  225  Sheets;    or,  14  x  20,  112  Sheets. 


TRADE  TEIJIM  .........        80  Ib  85  Ib 

APPROXIMATE  WIRE        \       No.  No. 

GAUGE.   .  .  ..........          33  32 

Wt.  pr.  Bo*,  Ibs  ____  .'      80.  85 

Size  of  Sheets        Sheet*  Ojor  box.  ' 

10  x!4.  ..  ......225  ,  80  85 

14  x20  .........  112   80,  85 

20  x28....  .....  112  160  170 

10  x20  .....  '....225  114  ,121 

11  x22  ......  ...225  138  147 

11^x23.  ..»:.'..  .225  151  161 

12  x24...  ......112   82  87 

13  x!3.  ......  .\225   97  103 

13  x26.  ..  ...  ..  .112   97  103 

14  x28  ........  .112  112  119 

15  x!5  .........  225  129  137* 

16  x!6...  ......  225  146  155 

17  x!7  ........  .^225  165  175 

18  x!8....  .....  112   93  98  , 

19  x!9  .....  ____  112  103  110 

20  x20.  ........  112  114  121 

21  x21...  ....  .  112  126  134 

22  x22...  .....  112  138  147 

23  x23.  ..  ..;,..  112  151  161 

ll£  164  175 

112  193  205 

112-   75  80 
89 
94 

16  x20  ......  ...112  .91  97 

14  x31  .........  112  124  132 

108 


90  Ib  95  Jh  100  Ib  1C  JXt  IX  IXX  1XIX  IXXXX 

No.  No.      No.  No.  No.  No.  No.  No.  No. 

3;  31         30  30  28  28  27  26  25 

90  95  100  107  128  135  155  175  195 


24     x24....,    . 
26    x26......  . 


14     x21. 


112 


14    x22.....  ..  ..112 


84 
88 


90  95 

90  95 

180  190 

129  136 

156  164 

170  179 

93  98 

109  115 

109  115 

126  133 

145  153 

165  174 

186  196 

104'  110 

116  122 

129"  136 

142  150 

156  164 

170  179 

185  195 

217  229 

85  89 

95  100 

99  105 

103  109 

140  147 

115  121 


100  107 

100  107 

200  214 

143  153 

172  184 

189  202 

103  110 

121  129 

121  129 

140  150 

161  172 

183  196 

206  221 

116  124 

129  138 

143  153 

158  169 

172  184 

189  202 

204,  220 

241  258 

94  100 

105  112 

110  118 

114  122 

155  166 

127  136 


128  135 

128  135 

256  270 

183  193 

222  234 

242  255 

132  139 

154  163 

154  163 

179  189 

206  217 

234  247 

264  279 

148  156 

165  174 

183  193 

202  213 

221  234 

242  255 

263  278 

309  326 


155  •  175  195 

155  175  195 

310  350  390 

221  250  279 

268  302  337 

293  331  368 

159  180  201 

187  211  235 

187  211  235 

217  245  273 

249  281  313 

283  320  357 

320  361  403 

179  202  226 

200  226  251 

221  250  279 

244  276  307 

268  202  337 

295  333  370 

320  360  40  L 

374  422  471 


-COST  OF  TIN  FOR  STANDING  SEAM  ROOFING. 

Size,  20x28  inches. 
Price  per  box,  per  square  foot  and  per  hundred  square  feet. 


When 

8.3. 

S.  S. 

When 

S.  S. 

S.  S. 

When 

S.  S. 

S.  S. 

Tin 
Costs. 

Roofing 
Costs. 

Roofing 
Coets. 

Tin 

Costs. 

Roofing 
Costs. 

Roofing 
Costs. 

Tin 
Costa. 

Roofing 
Costs. 

Roofing 
Costs. 

Box. 

Sq.  Ft. 

Sq. 

Box. 

Sq.  Ft. 

Sq. 

Box. 

Sq.  Ft. 

Sq. 

$  6.00 

.0162 

$1.62 

$12.50 

.0337 

$3.37 

$19.00 

.0513 

$5.13 

6.50 

.0175 

1.75 

13.00 

.0351 

3.51 

19.50 

.0526 

5.26 

7.00 

.0189 

1.89 

13  50 

.0364 

3.64 

20.00 

.0540 

5.40 

7  50 

.0202 

2.02 

14.00 

.0378 

3.78 

20.50 

.0553 

5.53 

8.00 

,0216 

2.16 

14.50 

.0391 

3.91 

21.00 

.0567 

5.67 

8.50 

.0230 

2.30 

15.00 

.0404 

.04 

21.50 

.0580 

5.80 

9.00 

.0243 

2.43 

15.50 

.0418 

.18 

22.00 

.0594 

5.94 

9.50 

.0256 

2.56 

16  00 

.0432 

.32 

22.50 

.0607 

6.07 

10.00 

.0270 

2.70      , 

16.50 

.0446 

.46 

23.00 

.0621 

6.21 

10.50 

.0283 

2.83 

17.00 

.0459 

.59 

23  50 

.0634 

6.34 

11.00 

.0297 

2.97 

17.50 

.0473 

73 

24.00 

.0648 

6.48 

11.50 

.0310 

3.10 

18.00 

.0486 

.86 

12  00 

.0324 

3-24 

18.50 

.0500 

5.00 

••• 

»  • 

The  above  estimates  do  not  include  cost  of  laying  material 


244 


WEIGHTS  AND  GAUGES  OF  SHEET  METALS 


20x28  STANDING  SEAM  TIN  ROOFING. 

Table  showing  quantity  of  20  x  28  tin  required  to  cover  a  given  number  of 
square  feet  with  Standing  Seam  Tin  Roofing. 

In  the  following  estimates  all  fractional  parts  of  a  sheet  are  treated  as  a  full 
sheet.  Full  size  of  sheet,  20  x  28,  locked  at  ends.  Covering  surface,  474.9  square 
inches,  or  3.3  square  feet. 


K 

Sheets 
required 

-I 

Sheets 
required 

jl 

i! 

I! 

02 

Sheets 
required  | 

8 

Sheets 
required  | 

4ft 

Sheets 
|  required  | 

d 

Sheets 
1  required  | 

1 

1  Sheets 
required  0 

i 

1 

19 

6 

37 

12 

55 

17 

73 

23 

91 

28 

145 

44 

270 

82 

2 

1 

20 

7 

38 

12 

56 

17 

74 

23 

92 

28 

150 

46 

280 

85 

3 

1 

21 

7 

39 

12 

57 

18 

75" 

23 

93 

29 

155 

47 

290 

88 

4 

2 

22 

7 

40 

13 

58 

18 

76 

24 

94 

29 

160 

49 

300 

91 

6 

2 

23 

7 

41 

13 

59 

18 

77 

24 

95 

29 

165 

50 

310 

94 

6 

2 

24 

8 

42 

13 

60 

19 

78 

24 

96 

30 

170 

52 

320 

97 

7 

3 

25 

8 

43 

14 

61 

19 

79 

24 

97 

30 

175 

54 

330 

100 

8 

3 

26 

8 

44 

14 

62 

19 

80 

25 

98 

30 

180 

55 

340 

103 

9 

3 

27 

9 

45 

14 

63 

20 

81 

25 

99 

30 

185 

57 

350 

106 

10 

4 

28 

9 

46 

14 

64 

20 

82 

25 

100 

31 

190 

58 

360 

109 

11 

4 

29 

9 

47 

15 

65 

20 

83 

26 

105 

32 

195 

60 

370 

112 

12 

4 

30 

10 

48 

15 

66 

20 

84 

26 

110 

33 

200 

61 

13 

4 

31 

10 

49 

15 

67 

21 

85 

26 

115 

35 

210 

64 

14 

5 

32 

10 

50 

16 

68 

21 

86 

27 

120 

37 

220 

67 

15 

5 

33 

10 

51 

16 

69 

21 

87 

27 

125 

38 

230 

70 

16 

5 

34 

11 

52 

16 

70 

22 

88 

27 

130 

40 

240 

73 

17 

6 

35 

11 

53 

17 

71 

22 

89 

27 

135 

41 

250 

76 

18 

6 

36 

11 

54 

17 

72 

22 

90 

28 

140 

43 

260 

79 

... 

... 

A  full  box,  20  x  28,  112  sheets,  will  cover  approximately  370  square  feet. 


SHEET 
20-JC23" 


29"x29J 


STOCK  SIZES  HEATER  PIPE  TIN. 
ROUND 

V  4*x9* 

8*  4*xlO| 

9*  4*xl2» 

10*  4*xl4* 

12*  4*xl7» 


SIZE  OF  SHEET  NECESSARY  TO  MAKE  4  PC.  ELBOWS 
7*— 12x23 
8*— 14x26 
9*— 14x29* 
10*—  15x32* 
W— 10*3* 


MISCELLANEOUS  TABLES 


245 


I 

r«    £l    ?l    »    ff§     "3"     -T     •*     iO     iO     <O     O 

P-  §  i  i  1  i  1  1  1 

s« 

Cl      lO      T      •-•      I1      1-      O      fO      '-O      Cl      Cl      I* 

»S     Cl     C>     O     CO     .-O     "*     1<     S     O     ^     tO 

'-O     »-H      -*<     t-     O     CO     tO     C> 
'fj      ?Z      t-      f-  '      O      O      "TOO 
Ot-t-OOKOO>0 

a 

f-^c*C'icicocoi«-»*<Tni3otootbt.~-t-GOQOC?* 

**a 

SSsiSSIlSSSll 

oo    oo    t-    «o    in    ift 

O      0      O      -f      30      CJ 

to    to    t-    t-    t-    eo 

0 

g  s  ?,  s  §  s  ,t  ri  5  fs  r.  o 

i-ii-<«Mc^c«eoco-i<i«i<o»ft 

(o  S  to  E-  t-     • 

da 

O'-O 

ci    oo    eo    d    7"    o    to    >-  i^icir-jo 

§o    5    t- 
to    to    to      •      ; 

«H 

lOCCCOcOCJICOt—     O      -i*     CO     »—  *     lO 
CO«OOgi^30COl^OCOt^O 

o    <ri    to      •      •      •            • 

•IJ    fl 

cc  vo 

2isasSISIS315 

11         :         :         : 

^                  00 

8SSo§S§?«S^22 

r1iH^-(C<(?jnClCOCOCO'<l<       •*< 

£    :        :        :        : 

2         «  J 

H        £5 

ClOOOO^*C1-^C*it-^»OCOr-  ) 

r-t-?iooc<m«>oco-ocici 

>-lp-li-li-(C4C4C)COCOCO?5'l> 

:     :          :     •     .     .     . 

tb 

o        d 

a        *• 

gSS5'S§ScoS»3S!"     ' 

r-tiHi-li-lCSCMeMeNCOCOCO 

H           .    . 

O        e  = 
2         too 

W       -•  • 

t-     Cl     O     O      £     O     CO     t-      Cl     O         ;         • 

CJ     Cl      -r<     t-     O      —      -*     to     d      i-l 

•      ;       |       ;      i      *      *       ; 

to 

w,Hr-lrti-lCNC>^c1 

:     :     '     :     :     •     :     :     : 

10  tO 

§3  S  g  "*  5S  L2  °  *°     '     '     :     :     :     :     :     :     :     :     ''     :     : 

**  *"  "  "*  rt  **  C1     :     •     t     ••     :     ::::::: 

10 

^w^coSSSo       

da 

-T   tO 

g^gw^g::::::;;:::;::: 

d 

S     r-l         

da 

CO  tO 

IOtOt-0        

d 

eo 

-*«oto      

:*::::,'••. 

da 

<*tO 

J5  5    I:::":::::: 

d 

CO             •            •            •            i            

1      o     1 

a     a     4     a     a     a 

to         to         <o         to         to         to 
*;  .«•  *;  +j  *?  «  -J  £  ^  «  *^  j 

a     a     a     a 

to         to         to         to 

d  d  d  d  d.  d  d  d  d 

COCOC»0»<^0££0« 

.s 
I 


246 


MISCELLANEOUS  TABLES 


(A 


2 


r-l<NCNJC^<MOJCOCO'*iOU><O 


Q     r-|     09     ^H     GO    rH 

C<J     M     O-l     <N     CX|     CO 


x 


oo 


r-l     iH     <M     <N     (N     CO     CO 


o 

8 


!N     C^l     <N     W    IN     CO 


i-l     (M     <N     <N 


COCCO«>--^'-lOO»O<NCiOCOO 
WCO^^WSWCOt-OOOOOSOrH 


MISCELLANEOUS  TABLES  247 

TABLE  OF   DIAMETERS   OF  WIRE1 

IN  DECIMAL  PARTS  OF  AN  INCH 
As  Represented  by  the  Various  Standard  Gauges. 


.No.  of  Wire> 

Washburn  and 
Moen  or 
A.  S.  &  W.  Co. 

X!  . 

§0 

American  or 
Brown  and  Sharpe 

Birmingham,  Stut 
Peck.  Stow  AW., 
or  British  Standa 

D.  8.  Standard.* 

[ 

000000 

.46 

.46875 

00000 

.43 

.4375 

0000 

.393 

r.454 

.46  ' 

.454 

.40625 

.400 

000 

.362 

.425 

41ft 

.425 

.375 

.372 

00 

.331 

.38 

-.365 

M 

.34375 

.348 

0 

.307 

.34 

.324 

.34 

.3125 

.32' 

1.1 

.283 

.289 

,3 

.28125 

.300 

,263 

i284 

.258 

(284 

.26562 

.276 

3 

.244 

.259 

.229 

.269 

.25 

.252 

4' 

225 

.238 

.204 

.238 

.23437 

.232 

5 

,207 

.22 

.182 

22 

.21875 

,212 

6 

,192 

.203 

.162 

1203 

•.  ?0312 

.192 

7 

177 

.18 

.144 

.18 

,1875 

,176 

8 

.162 

.165 

.128 

.165 

.17187 

,160 

9 

.148 

.148 

.114 

.148 

.  15625 

.144 

10 

.135 

.134 

.102, 

.134 

.14062 

.128 

11 

.12 

.12 

.091 

.12 

,125 

.116 

12 

.105 

.109 

.081  : 

.109 

.10937 

.104 

13 

.01)2 

.095 

.072 

.095 

.09375 

.092 

14 

.08 

.083 

.064 

.083 

.07812 

.080 

15 

.072 

.072 

.057  ! 

.072 

.07031 

.072 

16 

.063 

.065 

.051 

.065 

.064 

J7 

.054 

.058 

.045 

.058 

'.05625 

.056 

18 

,047 

.049 

.040 

.049 

.05 

.04B 

19 

.041 

.04 

.036' 

.042 

.04375 

.040 

20 

.035 

.035 

.032 

.035 

,0375 

.036 

21 

.032 

-.0315 

.028 

.032 

.03437 

.032 

22 

.028 

.0295 

.025 

.028 

.03125 

.028 

23 

.025 

.027 

.023 

.025 

.02812 

.024 

24 

.023 

.025 

.020 

.022 

.025 

.022 

25 

.02 

.023 

.018 

.02 

.02187 

.020 

26 

.018 

.0205 

.016 

,018 

.01875 

.018 

27 

.017 

.01875 

.014 

.016 

.01719 

.0164 

28 

.016 

.0165 

.01264 

.014 

.01562 

.0149 

29 

.015 

.0155 

.01126 

.013 

.01400 

.0136 

30 

\014 

.0137.5 

.01002 

.012 

.0125 

.0124 

31 

.0135 

;0122§ 

,00893 

,01 

.01094 

.0116 

32 

.013 

.01125. 

^00795 

.009 

.01016 

.0108 

33 

,OJ1 

.01025 

,00708 

.008 

.00937 

.0100 

34 

,01 

.0095'- 

'.-00630 

.007 

.00859 

.0092 

35 

.0095 

.009 

/00561, 

;;005. 

,00781 

.0081 

36 

.009 

.0075 

.005 

.<J04 

.00703 

.0076 

37 

.0085 

.0065 

.00445 

.00664 

.0068 

38 

.008 

.0057£ 

,00396 

.00625 

.0060 

39 

.0075 

.005 

.00353 



.0052 

40 

.0045 

.00314 

•  M.t  "i 

J.0048 

248 


MISCELLANEOUS  TABLES 


.393 


.362. 


Fig.  189 — Stubb's  Wire  Gauge. 


MlSCELLA N EOUS    TA IJLES 


249 


WEIGHT,  STRENGTH  AND  SIZE  OF  WIRE. 


Gauge 


Diatn. 


Approximate 
Size. 


Length 
of  63  tbs. 


Length 

of  100 

tbs. 


Length 

of  2000 

tbs. 


Length 
of  one 
carload, 
20,000 
tbs. 


Weight 
100 
feet 


Weight 
one 
mile 


Tensile 
Strength 


000 

00 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 


Ins. 
.362 
.331 
.307 
.283 
.263 
.244 
.225 
.207 
.192 
.177 
.162 
.148 
.135 
.120 
.105 
.092 
.080 
.072 
.063 
.054 
.047 
.041 
.035 


Inches. 
3-8  in.  scant 
11-32 
5-16 
9-32 

1-J 
7-32 


full 


3-16  " 
5-32  a   « 

1-8  in.  scant 
3-32  " 

1-16  • 
1-32  •  full 


Feet. 
181 
217 

228 

296 

343 

399 

470 

555 

647 

759 

905 

1,086 

1,304 

1,649 

2,168 

2,813 

3,728 

4,598 

6.000 

8,182 

10,862 

14,000 

19,687 


Feet. 

288 

344 

361 

471 

545 

634 

747 

881 

1,028 

1,205 

1,437 

1,724 

2,070 

2,618 

3,425 

4,464 

5.-917 

7,299 

9,524 

12,992 

17,241 

22,222 

31,250 


Feet. 

5.759 

6,886 

7.320 

9,425 

10,905 

12,674 

14,936 

17,621 

20.555 

24,096 

28,734 

34,483 

41,408 

52,356 

68,493 

89,286 

118,343 

145,985 

190,476 

259,740 

344,827 

444,444 

fi25,OCO 


Miles. 

11 

13 

14 

18 

21 

24 

28 

33 

39 

46 

54 

65 

78 

100 

130 

169 

224 

277 

360 

492 

653 

841 

1,185 


Lbs. 

34.73 

29.04 

27.66 

21.23 

18.34 

15.78 

13.39 

11.35 

9.73 

8.30 

6.96 

5.80 

4.83 

3.82 

2.92 

2.24 

1.69 


Lbs. 

1,834 

1.533 

1,460 

1.121 

968 

833 

707 

599 

514 

439 

367 

306 

255 

202 

154 

118 

89 

72 

55 

41 

31 

24 

17 


Lbs. 

9,755 

8,290 

6.880 

5,650 

4,930 

4,250 

3,620 

3040 

2,510 

2,220 

1,840 

1,560 

1,280 

1,000 

800 

668 

456 

352 

264 

208 

160 

128 

104 


Melting  Points  of  Different  Metals 

Antimony 951  degrees 

Bismuth 470  degrees 

Brass 1900  degrees 

Bronze 1692  degrees 

Copper      2548  degrees 

Glass 2377  degrees 

Gold  (pure) 2590  degrees 

I  ron  (cast)   3479  degrees 

I  ron  (wrought) 3980  degrees 

Lead    504  degrees 

Platinum 3080  degrees 

Silver  (pure)   1250  degrees 

Steel 2500  degrees 

Tin .  421  degrees 

Zinc 740  degrees 

Boiling  Points  of  Various  Fluids 

Ether 100  degrees 

Alcohol 173  degrees 

Sul.   Acid 240  degrees 

Refined  Petroleum 316  degrees 

Turpentine 304  degrees 

Sulphur         > 570  degrees 

Linseed  Oil 640  degrees 

Water  212  degrees 

Water  in  Vacuum 98  degrees 


25° 


MISCELLANEOUS  TABLES 


STANDARD  SIZES  OF  REGISTERS. 

Size  of 
Opening. 
4x6 
4x8 
4x10 

Size  of 
Opening.! 
6  x  30 
6  x  32 
7x7 

Size  of 
Opening. 

12  X  14 
12  X  15 
12  X  l6 

Size  of 
Opening. 
18x27 
18  x  30 
18x36 

4x12 

7x10 

12  X  17 

20  x  20 

4x13 
4x15 

7x12 
7X  14 

12  X  18 
12  X  19 

2O  X  23 
20  X  24 

4  x  18 

8x8 

12  X  2O 

20  X  26 

4  x  21 

8x10 

12  X  24 

20  X  28 

4x24 
5x8 

c  v  o 

8x  12 
8x14 
8x  16 

12  X  30 
12  X  36 
I4X   14 

20  x  30 
20  x  36 

21   X  2Q 

3  A  y 

r    v    T  O 

8x18 

14  x  16 

22  X  22 

5    A     1U 
SXI2 

8x  20 

I4X   18 

22  X  24 

s  x  14 

8x21 

14  x  20 

22  X  26 

3  •»  •«* 

•  c  x  16 

8  x  24 

14  X  22 

22  X  j8 

5x18 
6x6 

8x30 
9x9 

14  x  24 

16  x  16 

22  X  JO 

24  x  24 

6x8 
6x9 

9x12 
9  x  13 

16  x  18 
16  x  20 

24  X  27 

24X30 

6x10 
6x  12 
6  x  14 
6x16 

9x14 
9x16 
9x18 

IO  X  IO, 

16  X  22 

16  x  24 

16x28 

16  x  30 

24  x  32 
24  x  36 

27X27 
27X38 

6  x  18 

10  X  12 

16  x  32 

30X30 

6  x  20 

10  x  14. 

16  x  36 

30  x  36 

6  X22 

6  x  24 
6x28 

10  x  16 

10  x  i8f 

I  0  X  20\ 
12  X  12 

18  x  18 
i8x  21 
i8x  24 

30x42 
30x48 

•36  x  36 

•38x43 

•Made  to  order. 


DIMENSIONS  OF  REGISTERS 


Size  of 
opening, 

Nominal 

areaof 
opening. 

Effective 
area  of 
opening, 

Galv.  Iron  or 

Extreme 
dimensions  of 

Inches 

Square 
Inches 

Square 
Inches 

Inches 

6x10 

60 

40 

6»/i«  x  10e/ie 

71Viex  llHia 

8x10 

80 

53 

8%/x  10% 

9%x  11%' 

8x12 

96 

64 

8%  x  125/8 

9^*xl3% 

8x15 

120 

80 

8%xl5% 

9^4xl6Hi« 

9x12 

108 

72 

9'We  x  12*7*6 

107/8Xl37/8 

9x14 

126 

84 

9'Vi6xl4Hi6 

107/8Xl57/8 

10x12 

120 

80 

10*710  x!2Hie 

Hlr/i6x  13I5/i« 

10x14 

140 

93 

101W«xl41We 

ll^/iexl^U 

10x16 

160 

107 

LOHi«x  16*^6 

Hlf>i6xl77/» 

12x15 

180 

120 

1294x15% 

14Mox  17 

12x19 

228 

152 

123/i  x  1.9% 

1  4  Vie-  x  21 

14x22 

308 

205 

14T/s  x  22T/s 

16^x24^ 

15x25 

375 

250 

157/s  x  257/s 

17tfx27K 

16x20 

320 

213 

16%  x  207<8 

185/iox225/U 

16x24 

384 

256 

167/8X247/9 

18^iex26%« 

20x20 

400 

267 

2015/i6  x  20lr>lo 

22%  x  22% 

20x24 

480 

320 

20lf>io  x  2415/ia 

22%  x  26s/* 

20x26 

520 

347 

2015/ie  x  26ir>io 

22^8  x  28% 

21x29 

609- 

403 

2116/iex2915/io 

23%x31% 

27x27 

729 

486 

27lc/i6x27t5/io 

29%  x  29% 

27x38 

1026 

684 

27t(Ko  x  3816/xo 

29'%  x  40% 

30x30 

900 

600 

301BAe  x  301B/m 

32%  x  32-% 

Dimensions  of  different  makes  of  registers  vary 
slightly.  The  above  are  for  Tuttle  &  Bailey  Mfg. 
Co.'s  manufacture. 


MISCELLANEOUS  TABLES 


251 


TABLE  FOR  SIZE  OF  CONDUCTORS. 


Roof  Area 

Discharge  per                    Dia.  of  Pipe 

Area  in 

Insq.  ft 

sec.  in  cu.  ft. 

inches. 

in.  required. 

I2,OOO  

2.25   

63.61  .  .  . 

9 

10,000  

848  

52-5    ... 

9 

9,000  

75  

50.26.  .. 

8 

9,000  

66  

47-2  ... 

8 

8,000.  .  .  . 

48  

42      ... 

8 

7,250.  .  .  . 

35  

38.48... 

7 

7,000.  .  .  . 

21    

3^-7  ... 

7 

6,000  — 

IO   

3^-5  ... 

7 

5,250.... 

00    

28.28... 

6 

5,000.... 

0.92    

26.2  ... 

6 

4,000  

0.74    ,. 

21      ,  .  .  . 

6 

3,500.... 

0.70    

19.63... 

5 

3,000.  .  .  . 

0.55     v  ... 

15.9    ... 

5 

2,500  — 

0.45    .«,...;  

12.56... 

4 

2,000  

0.37    ,  

10.5    ... 

4 

1,225.... 

0.25  

7.06... 

3 

1,000  

O.l85  

5-25... 

3 

900.  .  .  . 

0.166  

47    ... 

3 

800.  ... 

0.15    

4.2    .... 

3 

700.... 

O.I2    

3-7  ... 

3 

600.... 

O.I  I    

.3-2  .., 

,  3 

500.  ... 

O.O92  ,... 

2.6 

3i 

400.  ... 

0.074  

2.1 

3! 

300.  ... 

0.055  

1.6  ... 

3 

200  

0.037  

1.0    ... 

3 

100,... 

0.018  

0.5  ... 

•••   3 

Square 

Feet  of  Surface  in  Round  Grates 

of  Different 

Diameters. 

•Inches. 

Feet. 

Inches. 

Feet.) 

13$..,..,. 

1 

26/,  ... 

3f 

15  

u 

27£    ... 

4 

164  

1} 

28      ... 

4*. 

18  

1$ 

28|    ... 

4$ 

19T3s  

2 

29$    ... 

4| 

20&  

2* 

3tVV  ... 

5 

21$  

2$ 

31$    ... 

5* 

22$  

2* 

33T3-  ... 

6 

23]  

3 

34$    ... 

64 

244  

31 

35}|  •••• 

7 

25  /6  

3* 

252 


MISCELLANEOUS  TABLES 


WEIGHTS  AND  MEASURES 


Troy  Weight. 

'24  grains  =  I  pwt. 
20  [  .vis.  =  i  ounce. 
12  ounces  r=  I  pound. 

Used  for  weighing  gold,  silver 
...id  jewels. 

Apothecaries'  Weight. 

20  grains  =  i  scruple. 
3  scruples  =  i  dram 
8  drams  =  I  ounce. 

12  ounces  =  i  pound. 

The  ounce  and  pound  in  this 
-are  the  same  as  in  Troy  weight. 

Avoirdupois  Weight. 

27  IJ-32  grains  =  i  dram,, 
1 6  drams  =  i  ounce. 
1 6  ounces  —  i  pound. 
25  pounds  =  i  quarter. 
4  quarters  =  i  cwt. 
2.000  Ibs.  =  i  short  ton. 
2,240  Ibs.  =  i  long  ton.  / 

Dry  Measure. 

2  pints  =  i  quart. 
8  quarts  =:  i  peck. 
4  pecks  =  i  bushel. 
36  bushels  =  i  chaldron. 

Liquid  Measure. 

4  gills  =  i  pint. 
2  pints  =  i  quart. 
4  quarts  =  i  gallon. 

gallons  =  i  barrel, 
barrels  =  i  hogshead; 


Circular  Measure. 

60  seconds  =  i  minute. 
6o~minutes  =r^  degree. 
30  degrees  =  i  sign. 
90  degrees  ~  i  quadrant. 
4  quadrants  =12  signs. 
360  degrees  =  i  circle. 

Long  Measure. 

12  inches  =  i  foot. 

3  feet  =  i  yard. 

5^2  yards  =  i  rod. 
40  rods  =•  i  furlong. 

8  furlongs  =  i  sta.  .mile* 

3  miles  =  i  league. 


Square  Measure. 

<T44  sq.  inches  =  'I  sq.  ft, 
9  sq.  feet  =  I  sq.  yard. 


-        -  . 

4OsSq.  rods=-i  rood. 
/   4  roods  =  i  acre. 
640  acres  —  i  sq.  mile. 

lime   Measure. 

60  seconds  =  i  minute 
60  minutes  =  i  hour. 
24  hours  =  i  day. 
7  days  =  i  week. 
28.  29,  30  or  31  days  =  I  "cal- 
endar-   month     (30    days  =  i 
month*  in  computing  interest) 

365  days  =  i  year. 

366  days  =  i  leap  year. 


MISCELLANEOUS  TABLES 


253 


TABLE  OF  MILLIMETERS  AND 
DECIMALS, 


Millimeter 


Decimal 
.02952 
.03937 
.04687 
.04921 
.05900 
.06250 
.07812 
.07874 
.08858 
.09375 
.09843. 
.11811 
.125 
.12795 
.1378 
.14062 
.157-18 
.17717 
.18750 
.19685 
.21654 
.23622 
...25 


Millimeter 

ft 


8 
9. 

10 
11 

12 

13 
14 
15 


19 
22 
25. 


Decimal 
.25591 
.27559 
.28125 
.3125 
.31496 
.35433 
.375 
.3937 
.43307 
.4375 
.47244 
.5 

.51181 
.55118 
.59055 
.59375 
.625 
.74803 
.75 

.86614 
.875 
'.98425 


Capacity  in  Gallons  and  Barrels  of  Round  Tanks  or  Cisterns 

of  Different  Diameters  12"  Deep. 
Diameter  of  Tank.  Gallons.  Barrels. 

2  feet 23.4    ..... 

2*    "    36.72 H 

3  "    52.87  If 

3*    "    71.96 2£ 

4  "    94.00 3 

4*    "    118.97 3£ 

5  "    14G.88 4$ 

5J    "    177.72 5f 

6  "    211.50 6$ 

6*    "    248.22 7$ 

7  "    287.85 9± 

7£    "    330.48 lOfc 

8  "    376.00 12 

8J    "    424.46 , 13J 

9  "    475.87 15^ 

9J    "    528.75 16| 

10  "    587.04 18f 

11  " 710.88 22J 

12  "    .  ...846,00..,  ...26* 


254 


MISCELLANEOUS  TABLES 


Horse  Power  of  Belting 


A  simple  rule  for  ascertaining  transmitting  power  of  belting  without  first  computing  speed 
rper  minute  that  it  travels,  is  as  follows: 

Multiply  diameter  of  pulley  in  inches  by  its  number  of  revolutions  per  minute,  and  thia 
product  by  width  of  the  belt  in  inches;  divide  the  product  by  3,300  for  single  belting,  or  by 
2. 100  for  double  belting,  and  the  quotient  will  be  the  amount  of  horse  power  that  tan  be  safely 
transmitted. 

TABLE  FOR  SINGLE  LEATHER,  FOUR-PLY  RUBBER  AND  FOUR-PLY 

COTTON  BELTING,  BELTS  NOT  OVERLOADED 

1  Inch  Wide,  800  Feet  per  Minute  =  1  Horse   Power, 


Speed 

WIDTH  OF  BELTS  IN  INCHES 

in  feet 

per 
Minute 

2 

3 

4 

5 

6 

8 

10 

12 

14 

16 

18 

90 

H.  P 

H.  P. 

H    P. 

H.  P. 

H.  P. 

H.  P. 

H,  P. 

H.  P. 

H.  P. 

H.  P. 

H.  P. 

H.  P. 

400 

1 

\\/2 

2 

2H 

3 

4 

5 

6 

7 

8 

9 

10 

600 

2ki 

3 

3K 

4H 

<} 

73^ 

9 

.ion 

12 

13/^ 

15 

800 

2  * 

3 

4 

5 

6 

8 

10 

12 

14 

18 

18 

20 

1000 

3?4 

£ 

6V4' 

7)^ 

10 

12}4 

15 

\iy2 

20 

22H 

25 

1200 

3  ^ 

4.l/2 

6 

7H 

9 

12 

15 

18 

21 

24 

27 

30 

1500 

5?'4 

7X2 

l?i* 

U  VS 

15 

18% 

22  H 

26  H 

30 

33% 

1800 

\yt 

6^4 

9 

13j^ 

18 

22^ 

27 

31/^ 

36 

403^ 

45 

2000 

5 

7^2 

10 

12  J^ 

15 

20 

25 

30 

35 

40 

45 

50 

2400 

6 

9 

12 

15 

18 

24 

30 

36 

42 

48 

54 

60 

2800 

7 

10  V2 

14 

\iy^ 

21 

28 

35 

42 

49 

56 

63 

70 

3000 

7¥t 

ilk' 

15 

18% 

22^ 

30 

37^ 

45 

52^ 

60 

67'H 

75 

3500 

13 

\iy2 

22 

26 

35 

44 

52*^ 

61 

70 

-79 

88 

4000 

io'4 

15 

20 

25 

30 

40 

50 

60 

70 

80 

90 

100 

4500 

11*4 

17 

22  y2 

28 

34 

45 

57 

69 

78 

90 

102 

114 

5000 

19 

25 

31 

37H 

50 

62^ 

75 

87  y2 

100 

112 

125 

Double  leather,  six-ply  rubber  or  six-ply  cotton  belting  will  transmit  50  to  75  per  cent,  more 
power  than  is  shgwn  ia  Ibis  table.    (One  incti  wide,  550  feet  per  minute  =  one  horse  power.) 


MISCELLANEOUS  TABLES 


255 


TABLE  OF  COMMON  FRACTIONS1 
AND  DECIMALS. 


Fraction 


Vie 
%4 
%2 

%-i 

VB 

%4 
5/32 


J%4 


2%4 


27/64 


Decimal 
.015625 
.03125 
.046875 
.0625 
.078125 
.09375 
.109375 
.125 
.1*0625 
.15625 
.171875 
.1875  ' 
.203125 
.21875 
.234375 
.25 

..265625 
.28125 
.296875 
.3125 
; 328125. 
.34375 
.359375 
i.375 
1.390625 
,40625 
.421875 
.4375 
.453125 
.46875  ' 
.484375 


Fraction 

33/64 
17/32 
3%4 


19/32 
;3%4 

4iL 
4%I 

JJie 
23/32*' 

47,4. 


49/64 
23/32 

13/i6 


57/64 
29/32 
5%4 
15/16 
>V64 
81/32 


1" 


Decimal 
.515625 
.53125 
.546875 
.5625 
.578125 
.59375 
.609375 
.625 
.640625 
.65625 
.67*1875 
.6875  • 
.703125 
.71875 
.734375 
.75 

.765625 
.78125 
.796875 
.8125 
.828125 
.84375 
.859375 
.875 
.890625 
.90625 
.921875 
.9375 
.953125 
.96875 
.984375 


256 


MISCELLANEOUS  TABLES 


TABLE  OF  A~REAS  AND  CIRCUMFERENCES  OF  CIRCLES 


Diam.           Cir.         Area 
Inches       Inches     Sq.  In. 

Diam.           Cir.         Area 
Inches       Inches     Sq.  In. 

Diam.           Cir.  ^."Area 
[nches       Inches       q.  In. 

ys        .393        .012 

16       50.26     201.06 

54     169.6     2290.2 

X        .785        .049 

16X  51.83'    213.82 

55     172.7     2375.8 

H     1-178        .110 

17       53.40-    226.98 

56     175.9     2463. 

X     1.570        .196 

17X  54.97     240.52 

57     179.       2551.7 

%     1.963       .307 

18       56.54     254.46 

58     182.2     2642. 

X     2.356        .442 

18X  58.11     268.80 

59     185.3     2733  9 

Y8     2.748        .601 

19       59.69     283.52 

60     188.4     2827.4 

1         3.141        .785 

19X61-26     298.64 

61     191.6     2922.4 

\Ys     3.534       .994 

20       62.83     314.16 

62     194.7     3019. 

IX     3.927     1.227 

20X  64.40     330.06 

63     197.9     3117.2 

\Ys     4.319     1.484 

21       65.97     346.36 

64     201.        3216.9 

IX     4.712     1.767 

21X  67.54     563.05 

65     204.2     3318.3 

iys     5.105     2.073 

22       69.11     380.13 

66     207.3     3421.2 

IK     5.497     2.405 

22X  70.68     397.60 

67     210.4     3525.6 

IJi     5.890     2.761 

23       72.25     415.47 

68     213.6     3631.6 

2         6.283     3.141 

23X  73.82     433.73 

69     216.7     3739.2 

2X    7.068     3.976 

24       75.39     452.39 

70     219.9     3848.4 

2X     7.854     4.908 

24X  76.96     471.43 

71     233.        3959.2 

2K     8.639     5.939 

25       78.54     490.87 

72     226.1     4071.5 

3         9.424     7.068 

26       81.68     530.93 

73     229.3     4185.3 

3X  10.21       8.295 

27       84.82     572.55 

74     232.4     4300.8 

3X  10.99       9.621 

28       87.96     615.75 

75     235.6     4417.8 

3K  11.78     11.044 

29       91.10     660.52 

76     238.7     4536.4 

4       12.56     12.566 

30       94.24     706.86 

77     241.9     4656.6 

4X   14.13     15.904 

31       97.38     754.76 

78     245.       4778.3 

5       15.70     19.635 

32     lOO.o       840.24 

79     248.1     4901.6 

5X  17-27     23.578 

33     103.6       855.30 

80     251.3     5026.5 

6       18.84     28.274 

34     106.8       907.92 

81     254.4     5153. 

6X  20.42     33.183 

35     109.9       962.11 

82     257.6     5281. 

7       21.99     38.484 

36     113.       1017.8 

83     260.7     5410.6 

7X  23.56     44.178 

37     116.2     1076  2 

84     263.8     5541.7 

8       25.13     50.265 

38     119.3     1134.1 

85     267.        5674.5 

8X  26.70     56.745 

39     122.5     1194  5 

86     270.1     5808.3 

9       28.27     63.617 

40     125.6     1256  6 

87     273.3     5944.6. 

9X  29.84     70.882 

41     128.8     1320.2 

88     276.4    6082.  1> 

10       31.41     78.539 

42     131.9     1385.4 

89     279.6     6221.1 

10X  32.98     86.590 

43     135.       1452.2 

90     282.7     6361.7 

11       34.55     95.033 

44     138.2     1520.5 

91     285.8     6503.8 

11X  36.12  103.86 

45     141.3     1590.4 

92     289.       6647.6 

12       37.69  113.09 

46     144.5     1661.9 

93     292.1     6792.9 

12X  39.27  122.71 

47     147.6     1734.9 

94     295.3     6939.7 

13       40.84  132.73 

48     150.7     1809.5 

95     298,.  4     7088.2 

13X  42.41   143.13 

49     153.9     1885.7 

96     301.5     7238.2 

14       43.98  153.93 

50     157.        1963.5 

97     304.7     7389  8 

14X  45.55  165.13 

51     160.2     2042.8 

98     307.8     7542,9 

15       47.12  176.71 

52     163.3     2123.7 

99     311.        7697.7 

15X  48.69  188.69 

53     166.5     2206.1 

100     314,1     7853.9 

MISCELLANEOUS  TABLES  257 


Rules  Relative  to  the  Circle 

To  Find  Circumference: 

Multiply  diameter  by  3.1416. 
Or  divide  diameter  by  0.3183. 

To  Find  Diameter: 

Multiply  circumference  by  0.3183. 
Or  divide   circumference  by  3.1416. 

To  Find  Radius: 

Multiply  circumference  by  0.15915. 
Or  divide   circumference  by  6.28318. 

To  Find  Size  of  an  Inscribed  Square: 

Multiply  diameter  by  0.7071. 

Or  multiply  circumference  by  0.2251. 

Or  divide  circumference  by  4.4428. 

To  Find  Side  of  an  Equal  Square: 

Multiply  diameter  by  0.8862. 

Or  divide  diameter  by  1.1284. 

Or  multiply  circumference  by  0.2821. 

Or  divide  circumference  by  3.545. 

Square: 

A  side  multiplied  by  1.4142  equals  diameter  of  its  cir- 
cumscribing circle. 

A  side  multiplied  by  4.443  equals  circumference  of  its 
circumscribing  circle. 

A  side  multiplied  by  1.128  equals  diameter  of  an  equal 
circle. 

A  side  multiplied  by  3.545  equals  circumference  of  an 
equal  circle. 

Square  inches  multiplied  by  1.273  equals  circle  inches  of 
an  equal  circle. 

To  Find  the  Area  of  a  Circle: 

Multiply  circumference  by  one-quarter  of  the  diameter. 
Or  multiply  the  square  of  diameter  by  0.7854. 
Or  multiply  the  square  of  circumference   by  0.07958. 
Or  multiply  the  square  of  one-half  diameter  by  3.1416. 

To  Find  the  Area  of  an  Ellipse: 

Multiply  the  product  of  its  axes  by  .785398. 

Or  multiply  the  product  of  its  semi-axes  by  3.14159. 

Contents  of  cylinder  area  =  area  of  end  X  length. 

Contents  of  wedge  =  area  of  base  X  one-half  altitude. 

Surface  of  cylinder  —  length  X  circumference  -f-  area  of  both 
ends. 

Surface  of  sphere  =  diameter  squared  X  3'I4!6,  or  =  diame- 
ter X  circumference. 

Contents  of  sphere  =  diameter  cubed  X  0.52.36. 

Contents    of   pyramid    or   cone,   right    or   oblique,    regular   or 
irregular  =  area  of  base  X  one-third  altitude. 

Area  of  triangle  =  base  X  one-half  altitude. 

Area  of  parallelogram  =  base  X  altitude. 

Area  of  trapezoid  —  altitude  X  one-half  the  sum  of  parallel 
sides. 


258 


MISCELLANEOUS  TABLES 


CUBICAL    CONTENTS    OF    ROQMS 

HAVING    CEILINGS    OF    THE    FOLLOWING    HEIGHTS 


.Floor  Area 

8  ft. 

8%  ft. 

Oft. 

Ofc.ft. 

10  ft. 

10V&  it. 

11  ft. 

12  ft. 

3 

3 

72 

77 

81 

85 

90 

95 

99 

108 

3 

3# 

84 

89 

95 

99 

105 

110 

115 

120 

3 

4 

96 

102 

108 

114 

120 

126 

132 

144 

3 

4% 

108 

115 

122 

128 

135 

142 

148 

162 

3 

5 

120 

128 

135 

142 

150 

158 

16,5 

180 

3 

5% 

132 

140 

149 

156 

165 

173 

18-1 

198 

3 

6 

144 

153 

162 

171 

ISO 

189 

198' 

210 

3& 

3V6 

98 

104 

110 

116 

123 

129 

'134' 

147 

3y2 

4 

112 

119 

126 

133 

140 

147 

154 

168 

3% 

4% 

126 

134 

142 

149 

158 

165' 

173 

189 

3% 

5 

140 

149 

158 

166 

175 

184 

192 

210 

3% 

X 

5% 

154 

164 

173 

182 

193 

202 

211' 

231 

3% 

X 

6 

168 

179 

ISO 

199 

210 

221 

231 

252 

3V2 

X 

6M. 

182 

193 

205 

216 

22S 

239 

250 

273 

3^ 

7 

196 

208 

221 

232 

245 

257 

2G9 

294 

4 

4 

128 

136 

144 

152 

100 

168 

176 

192 

4 

4^ 

144 

153 

162 

171 

ISO 

189 

19$ 

216 

4 

5 

160 

170 

ISO 

190 

200 

210 

220 

240 

4 

5V6 

176 

187 

198 

209 

220 

231 

242 

264 

4 

6 

192 

204 

216 

228 

240 

252 

264 

288 

4 

6ya 

208 

221 

234 

247 

260 

273 

2S6 

312 

4 

7 

224 

238 

252 

266 

250 

294 

308 

336 

4 

X 

7.% 

240 

255 

270 

285 

300 

315 

330 

360 

4 

X 

8 

256 

272 

288 

304 

320 

336 

352 

3S4 

4V£ 

X 

4ya 

162 

172 

182 

192 

203 

213 

2^)9 

243 

4y2 

X 

5 

180 

191 

203 

213 

225 

236 

247 

270 

4%. 

X 

5% 

198 

210 

223 

235 

248 

260 

272 

297 

4y2 

X 

6 

216 

230 

243 

2.56 

270 

2S4 

297 

324 

4y2 

X 

ey2 

234 

249 

263 

277 

293 

307 

321 

351 

4y2 

X 

7 

252 

268 

284 

299 

315 

331 

346 

378 

4% 

X 

.7% 

270 

287 

304 

320 

338 

354 

371 

405 

4y2 

X 

8 

288 

306 

324 

342 

360 

378 

396 

432 

iy2 

X 

8Ms 

306 

325 

344 

363 

383 

402 

420 

459 

4y2 

X 

9 

324 

345 

3«5 

384 

405 

425 

445 

4S6 

5 

X 

5 

200 

212 

225 

237. 

250 

263 

275 

300 

5 

X 

.6% 

220 

234 

248 

261 

275 

289 

302 

330 

5 

X 

6 

240 

255 

270 

285 

300 

315 

330 

360 

5 

X 

6% 

260 

276 

293 

308 

325 

341 

357 

390 

5 

X 

7 

280 

297 

315 

332 

350 

368 

3S5 

420 

5 

X 

7V6 

300 

319 

338 

358 

375 

394 

412 

450 

5 

X 

8 

320 

340 

360 

380 

400 

420 

440 

480 

5 

X 

sy2 

340 

361 

3S3 

403 

425 

446 

467 

510 

5 

X 

9 

360 

382 

405 

427 

450 

473 

495 

540 

5 

X 

»% 

380 

404 

428 

451 

475 

499 

522 

570 

6 

X 

10 

400 

425 

450 

475 

500 

525 

550 

600 

5% 

X 

•5% 

242 

257 

272 

287 

303 

318 

332 

363 

5% 

X' 

6 

264 

281 

297 

313 

330 

347 

363 

396 

5tf 

X 

6% 

286 

304 

322 

339 

358 

375 

393 

429 

5% 

* 

7 

308 

327 

347 

365 

385 

404 

423 

462 

5% 

£ 

7% 

330 

351 

371 

391 

413 

433 

453 

495 

5y2 

X 

8 

352 

374 

396 

418 

440 

462 

4S4 

523 

5% 

X 

£% 

374 

397 

421 

444 

468 

491 

514 

561 

sy3 

X 

r 

396 

421 

446 

470 

495 

520 

544 

504 

5% 

X 

9% 

418 

444 

470 

496 

523 

549 

574 

627 

MISCELLANEOUS  TABLES 


259 


CUBICAL    CONTENTS    OF    ROOMS 

HAVING    CEILINGS    OF    THR    FOLLOWING    HEIGHTS 


Floor  Area 

8  ft. 

8%  ft. 

9ft. 

9%  ft. 

10ft. 

10%  ft 

lift. 

12ft. 

5% 

X 

10 

440 

468 

495 

522 

550 

578 

605 

660 

5% 

X 

10% 

462 

491 

520 

548 

578 

606 

635 

693 

5% 

X 

11 

4&4 

514 

545 

574 

605 

635 

665 

726 

6 

X 

6 

288 

306 

324 

342 

360 

378 

396 

432 

6 

X 

6% 

312 

332 

351 

370 

390 

410 

429 

468 

6 

X 

7 

336 

357 

378 

399 

420 

441 

462 

604 

6 

X 

7% 

360 

383 

405 

427 

450 

473 

495 

540 

6 

X 

8 

384 

408 

432 

456 

480 

504 

528 

576 

6 

X 

8% 

408 

434 

459 

484 

510 

536 

561 

612 

6 

X 

9 

432 

459 

486 

513 

540 

567 

594 

648 

6 

X 

9% 

456 

485 

513 

541 

570 

599 

627 

684 

6 

X 

10 

480 

510 

540 

570 

600 

630 

660 

720 

6 

X 

10  y3 

504 

536 

567 

598 

630 

662 

693 

756 

G 

X 

11 

528 

561 

594 

627 

660 

693 

726 

792 

6 

X 

11% 

552 

587 

621 

655 

690 

725 

759 

828 

6 

X 

12 

576 

612 

648 

684 

720 

756 

792 

864 

6% 

X 

6% 

338 

359 

380 

401 

423 

444 

464 

507 

6% 

X 

7 

364 

387 

410 

432 

455 

478 

500 

546 

6% 

X 

7% 

390 

414 

439 

463 

488 

512 

636 

685 

0% 

X 

8 

416 

442 

468 

494 

520 

546 

572 

624 

6y2 

X 

8% 

442 

470 

497 

524 

553 

580 

607 

663 

6% 

X 

9 

468 

497 

527 

555 

585 

615 

643 

702 

6% 

X 

9% 

494 

525 

556 

586 

618 

648 

679 

741 

6% 

X 

10 

520 

553 

585 

617- 

650 

683 

715 

780 

6% 

X 

10  y2 

546 

580 

614 

648 

683 

717 

750 

€19 

6% 

X 

11 

572 

608 

644 

679 

715 

751 

786 

S58 

6% 

X 

11% 

598 

035 

673 

710 

748 

785 

822 

897 

6% 

X 

12 

624 

663 

702 

741 

780 

819 

858 

956 

6% 

X 

i2y2 

650 

691 

731 

771 

813 

853 

893 

975 

ey2 

X 

13 

676 

718 

761 

802 

845 

887 

929 

1014 

7 

X 

7 

392 

417 

441 

465 

490 

515 

539 

588 

7 

X 

7% 

420 

446 

473 

498 

525 

651 

677 

630 

7 

X 

8  . 

448 

476 

504 

532 

560 

688 

616 

672 

7 

X 

8% 

476 

506 

536 

5.65 

50G 

£25 

654 

714 

7 

X 

9 

504 

536 

557 

59-8 

630 

662 

693 

756 

7 

X 

9% 

532 

565 

599 

631 

665 

698 

731 

798 

7 

X 

10 

560 

595 

630 

665 

700 

736 

770 

840 

7 

X 

10% 

588 

625 

662 

698 

735 

772 

808 

882 

7 

X 

11 

616 

655 

693 

731 

770 

809 

847 

924 

7 

X 

11% 

644 

684 

725 

764 

806 

845 

885 

966 

7 

X 

12 

672 

714 

756 

798 

840 

882 

924 

1008 

7 

X 

12% 

700 

744 

788 

831 

875 

919 

962 

1050 

7 

X 

13 

728 

774 

819 

864 

910 

956 

1001 

1092 

7 

X 

13% 

756 

803 

851 

«97 

945 

992 

1039 

1134 

7 

X 

14 

784 

833 

882 

931 

980 

.029 

1078 

1176 

7% 

X 

T% 

450 

478 

506 

534 

563 

591 

618 

675 

7% 

X 

8 

480 

510 

540 

670 

600 

630 

660 

720 

7% 

8% 

510 

642 

574 

005 

638 

669 

701 

766 

7% 

9 

540 

574 

608 

641 

675 

709 

742 

810 

7% 

9% 

570 

606 

641 

676 

713 

748 

783 

855 

7% 

10 

600 

638 

675 

712 

750 

788 

825 

900 

7% 

10% 

630 

669 

709 

748 

788 

827 

866 

945 

7% 

11 

660 

701 

743 

783 

825 

866 

907 

990 

7% 

11% 

690 

733 

776 

819 

863 

906 

948 

1035 

260  MISCELLANEOUS  TABLES 

CUBICAL    CONTENTS    OF    ROOMS 

HAVING    CEILINGS   OF    THE    FOLLOWING    HEIGHTS 


Floor  Area 

8  ft. 

8V^  ft. 

9  ft. 

9Vfe  ft. 

10  ft. 

10%  ft. 

lift. 

12ft. 

% 

X 

12 

720 

765 

810 

855 

900 

945 

990 

1080 

K 

x 

12% 

750 

797 

844 

890 

938 

984 

1031 

1125 

% 

X 

13 

780 

829 

878 

926 

975 

1024 

1072 

1170 

% 

31 

13  1/2 

810 

861 

911 

961 

1013 

1063 

1113 

1215 

l/o 

X 

14 

840 

893 

945 

997 

1050 

1103 

1155 

1260 

l/2 

X 

14%, 

870 

924 

979 

1033 

1088 

1142 

1196 

1305 

V2 

X 

15 

000 

956 

1013 

1068 

1125 

1181 

1237 

1350 

8 

X 

8 

512 

544 

576 

608 

640 

672 

704 

768 

8 

X 

8y3 

544 

578 

612 

646 

680 

714 

748 

816 

8 

X 

9 

576 

612 

648 

684 

720 

756 

792 

864 

8 

X 

9% 

608 

646 

684 

722 

760 

798 

836 

912 

8 

X 

10 

640 

680 

720 

760 

800 

840 

880 

960 

8 

X 

ioy2 

672 

714 

756 

798 

840 

882 

924 

1008 

8 

X 

11 

704 

748 

792 

836 

880 

924 

968 

1056 

8 

X 

11  »/2 

736 

782 

828 

874 

920 

966 

1012 

1104 

8 

X 

12 

768 

816 

864 

912 

960 

1008 

1056 

1152 

8 

X 

12% 

800 

850 

900 

950 

1000 

1050 

1100 

1200 

8 

X 

13 

832 

884 

936 

988 

1040 

1092 

1144 

1248 

8 

X 

is  y2 

864 

918 

972 

1026 

1080 

1134 

1188 

1296 

8 

X 

14 

896 

952 

1008 

1064 

1120 

1176 

1232 

1344 

8 

X 

14% 

928 

986 

1044 

1102 

1160 

1218 

1276 

1392 

8 

X 

15 

960 

1020 

1080 

1140 

1200 

1260 

1320 

1440 

8 

X 

is  y2 

992 

1054 

111G 

1178 

1240 

1302 

1364 

1488 

8 

X 

16 

1024 

1088 

1152 

1216 

1280 

1344 

1408 

1536 

s% 

X 

8% 

578 

614 

650 

686 

723 

759 

794 

867 

8% 

X 

9 

612 

650 

689 

726 

765 

803 

841 

918 

8% 

X 

9% 

646 

686 

727 

767 

808 

848 

888 

969 

8% 

X 

10 

680 

723 

765 

807 

850 

893 

935 

1020 

8y2 

X 

iov£ 

714 

759 

803 

847 

893 

937 

981 

1071 

8% 

X 

11 

748 

795 

842 

888 

935 

982 

1028 

1122 

8% 

X 

11% 

782 

831 

880 

928 

978 

1026 

1075 

1173 

8y4 

X 

12 

816 

867 

918 

969 

1020 

1071 

1122 

1224 

8V2 

X 

12% 

850 

903 

95$ 

1009 

1063 

1116 

1168 

1275 

8V2 

X 

13 

884 

939 

995 

1049 

1105 

1160 

1215 

1326 

8% 

X 

13% 

918 

975 

1033 

1090 

1148 

1205 

1262 

1377 

sy2 

X 

14 

952 

1012 

1071 

1130 

1190 

1250 

1309 

1428 

sy2 

X 

14% 

986 

1048 

1109 

1170 

1233 

1294 

1355 

1479 

sy2 

X 

15 

1020 

1084 

1148 

1211 

1275 

1339 

1402 

1530 

sy2 

X 

15% 

1054 

1120 

1186 

1251 

1318 

1383 

1449 

1581 

sy2 

X 

16 

1088 

1156 

1224 

1292 

1360 

1428 

1496 

1632 

8y2 

X 

16% 

1122 

1192 

1262 

1332 

1403 

1473 

1542 

1683 

sy2 

X 

17 

1156 

1228 

1301 

1372 

1445 

1517 

1589 

1734 

9 

X 

9 

648 

689 

729 

769 

810 

851 

891 

972 

9 

X 

9% 

684 

727 

770 

812 

855 

898 

940 

1026 

9 

X 

10 

720 

765 

810 

855 

900 

945 

990 

1080 

9 

X 

10% 

756 

803 

851 

897 

945 

992 

1039 

1134 

9 

X 

11 

792 

842 

891 

940 

990 

1040 

1089 

1188 

9 

X 

11% 

828 

880 

932 

982 

1035 

1087 

1138 

1242 

9 

X 

12 

864 

918 

972 

1026 

1080 

1134 

1188 

1296 

9 

X 

12% 

900 

956 

1013 

1068 

1125 

1181 

1237 

1350 

9 

z 

13 

936 

995 

1053 

1111 

1170 

1229 

1287 

1404 

9 

X 

13% 

972: 

1033 

1094 

1154 

1215 

1276 

1336 

1458 

9 

i 

14 

1008 

1071 

1134 

1197 

1260 

1323 

1386 

1512 

9 

X 

14% 

1044 

1109 

1175 

1239 

1305 

1370 

1435 

1666 

MISCELLANEOUS  TABLES 


261 


CUBICAL    CONTENTS    OF    ROOMS 

HAVING    CEILINGS    OF    THE    FOLLOWING    HEIGHTS 


Floor  Area 

8  ft. 

8%  ft. 

9  ft. 

9&  ft. 

10  ft. 

10  Vz  ft. 

H  ft. 

12  ft. 

9 

X 

13 

1080 

1148 

1215 

1282 

1350 

1418 

1485 

1620 

9 

X 

15  % 

1116 

1186 

1256 

1325 

1395 

1465 

1534 

1674 

9 

X 

16 

1152 

1224 

1296 

1368 

1440 

1512 

15S4 

1728 

9 

X 

ioya 

1188 

1262 

1337 

1410 

1485 

1559 

1633 

I7t>2 

9 

X 

17 

1224 

1301 

1377 

1453 

1530 

1607 

1683 

1836 

9 

X 

17  ya 

1200 

1339 

1418 

1496 

1575 

1654 

1732 

1890 

9 

X 

18 

1206 

1377 

1458 

1539 

1620 

1701 

1782 

1944 

9% 

X 

9y2 

722 

767 

812 

857 

903 

948 

992 

1083 

9% 

X 

10 

760 

808 

855 

902 

950 

998 

1045 

1140 

9y2 

X 

10  y2 

798 

848 

898 

947 

998 

1047 

1097 

1197 

9% 

X 

11 

836 

888 

940 

992 

1045 

1097 

1149 

1254 

9y2 

x; 

11% 

874 

929 

983 

1038 

1093 

1147 

1201 

1311 

9y, 

X 

12 

912 

969 

1026 

1083 

1140 

1197 

1254 

1368 

9% 

X 

12  y2 

950 

1009 

1069 

1128 

11S8 

1247 

1306 

1425 

9% 

X 

13 

988 

1050 

1111 

1173 

1235 

1297 

1358 

1482 

9V2 

X 

i3ya 

1026 

1090 

1154 

1218 

1283 

1347 

1410 

1539 

9% 

X 

14 

1064 

1131 

1197 

1263 

1330 

1397 

1463 

1596 

9y2 

X 

14  y2 

1102 

1171 

1240 

1308 

1378 

1446 

1515 

1653 

9% 

X 

15 

1140 

1211 

1282 

1353 

1425 

1496 

1567 

1710 

9% 

15% 

1178 

1252 

1325 

1398 

1473 

1546 

1619 

1767 

9% 

16 

1216 

1292 

1368 

1444 

1520 

1596 

1672 

1824 

9y2 

16  ya 

1254 

1332 

1411 

1489 

1568 

1646 

1724 

1881 

9y2 

17 

1292 

1373 

1453 

1534 

1615 

1696 

1776 

1938 

9v2 

17% 

1330 

1413 

1496 

1579 

1663 

1746 

1828 

1995 

9y2 

18 

1368 

1454 

1539 

1624 

1710 

1796 

1S81 

2052 

9y2 

X 

18Va 

1406 

1494 

1582 

1669 

1758 

1845 

1933 

2109 

9y2 

X 

19 

1444 

1534 

J.625 

1714 

1805 

1895 

1985 

2160 

10 

X 

10 

800 

850 

900 

950 

1000 

1050 

1100 

1200 

10 

X 

10% 

840 

893 

945 

997 

1050 

1103 

1155 

1260 

10 

X 

11 

880 

935 

990 

1045 

1100 

1155 

1210 

1320 

10 

X 

11% 

920 

978 

1035 

1092 

1150 

1208 

1265 

1380 

10 

12 

960 

1020 

1080 

1140 

1200 

1260 

1320 

1440 

10 

i2ya 

1000 

1063 

1125 

1187 

1250 

1313 

1375 

1500 

10 

13 

1040 

1105 

1170 

1235 

1300 

1365 

1430 

1560 

10 

13% 

1080 

1148 

1215 

1282 

1350 

1418 

14H5 

1620 

10 

14 

1120 

1190 

1260 

1330 

1400 

1470 

15*40 

1680 

10 

14% 

1160 

1233 

1305 

1377 

1450 

1523 

1595 

1740 

10 

X 

15 

1200 

1275 

1350 

1425 

1500 

1575 

1650 

1800 

10 

X 

15  ya 

1240 

1318 

1395 

1472 

issa 

1628 

1705 

1800 

10 

X 

16 

1280 

1360 

1440 

1520 

1600 

1680 

1760 

1920 

10 

X 

16% 

1320 

1403 

14S5 

1567 

1650 

1733 

1815 

1980 

10 

X 

17 

1360 

1445 

1530 

1615 

1700 

1785 

1870 

2040 

10 

X 

17  y2 

1400 

148S 

1575 

1662 

1750 

1838 

1925 

2100 

10 

X 

18 

1440 

1530 

1620 

1710 

1800 

1890 

1980 

2160 

10 

X 

18% 

1480 

1573 

1665 

1757 

1850 

1943 

2035 

2220 

10 

X 

19 

1520 

1615 

1710 

1805 

1900 

1995 

2090 

2280 

10 

X 

19% 

1560 

1658 

1755 

1852 

1950 

2048 

2145 

2340 

10 

X 

20 

1600 

1700 

1800 

1900 

2000 

2100 

2200 

2400 

11 

X 

11 

968 

1029 

1089 

1149 

1210 

1271 

1331 

1452 

11 

X 

12 

1056 

1122 

1188 

1254 

1320 

1386 

1452 

1584 

11 

z 

13 

1144 

1216 

1287 

1358 

1430 

1502 

1573 

1716 

11 

X 

14 

1232 

1309 

1386 

1463 

1540 

1617 

1694 

1848 

Hi 

X 

IS 

1320 

1403 

1485 

1567 

1650 

1733 

1815 

1980 

11 

z 

16 

1408 

1496 

1584 

1672 

1760 

1848 

1936 

2112 

262 


MISCELLANEOUS  TABLES 


CUBICAL    CONTENTS    OF    ROOMS 

HAVING    CEILINGS    OF    THE    FOLLOWING    HEIGHTS 


Floor  Area 

8  ft. 

sy2  ft. 

9ft. 

9%  ft. 

10ft. 

10%  ft. 

11  ft. 

12ft. 

11 

X 

17 

1496 

1590 

1683 

1776 

1870 

1964 

2057 

2244 

11 

X 

18 

1584 

1683 

1782 

1881 

1980 

2079 

2178 

2376 

11 

X 

19 

1672 

1777 

1881 

1986 

2090 

2195 

2299 

2508 

11 

X 

20 

1760 

1870 

1980 

2090 

2200 

2310 

2420 

2640 

11 

X 

21 

1848 

1964 

2079 

2194 

2310 

2426 

2541 

2772 

11 

X 

22 

1936 

2057 

2178 

2299 

2420 

2541 

2662 

2904 

12 

X 

12 

1152 

1224 

i29e 

1368 

1440 

1512 

1584 

1728 

12 

X 

13 

1248 

1326 

1404 

1482 

1560 

1638 

1716 

1872 

12 

X 

14 

1344 

1428 

1512 

1596 

1680 

1764 

1848 

2016 

12 

X 

15 

1440 

1530 

1620 

1710 

1800 

1890 

1980 

2160 

12 

X 

16 

1536 

1632 

1728 

1824 

1920 

2016 

2112 

2304 

12 

X 

17 

1632 

1734 

1836 

1938 

2040 

2142 

2244 

244S 

12 

X 

18 

1728 

1836 

1944 

2052 

2160 

2268 

2376 

2592 

12 

X 

19 

1824 

1938 

2052 

2166 

2280 

2394 

2508 

2736 

12 

X 

20 

1920 

2040 

2160 

2280 

2400 

2520 

2640 

2880 

12 

X 

21 

2016 

2142 

2268 

5394 

2520 

2646 

2772 

3024 

12 

X 

22 

2112 

2244 

2376 

-2508 

2640 

2772 

2904 

3168 

12 

X 

23 

2208 

2346 

2484 

2622 

2760 

2898 

3036 

3312 

12 

X 

24 

2304 

2448 

2592 

2736 

2880 

3024 

3168 

3456 

13 

X 

13 

1352 

1437 

1521 

1605 

1690 

1775 

1859 

2028 

13 

X 

14 

1456 

1547 

1638 

1729 

1820 

1911 

2002 

2184 

13 

X 

15 

1560 

1658 

1755 

1852 

1950 

2048 

2145 

2340 

13 

X 

16 

1664 

1768 

1872 

1976 

2080 

2184 

2288 

2496 

13 

X 

17 

1768 

1879 

1989 

2099 

2210 

2321 

2431 

2652 

13 

X 

18 

1872 

1989 

2106 

2223 

2340 

2457 

2574 

2808 

13 

X 

19 

1976 

2100 

2223 

2346 

2470 

2594 

2717 

2964 

13 

X 

20 

2080 

2210 

2340 

2470 

2600 

2730 

2860 

3120 

13 

X 

21 

2184 

2321 

2457 

2593 

2730 

2867 

3003 

3276 

13 

X 

22 

2288 

2431 

2574 

2717 

2860 

3003 

3146 

3432 

13 

X 

23 

2392 

2542 

2961 

2840 

2990 

3140 

3289 

3588 

13 

X 

24 

2496 

2652 

2808 

2964 

3120 

3276 

3432 

3744 

13 

X 

25 

2600 

2763 

2925 

3087 

3250 

3413 

3575 

3900 

13 

X 

26 

2704 

2873 

3042 

3211 

3380 

3549 

3718 

4056 

14 

X 

14 

1568 

1666 

1764 

1862 

1960 

2058 

2156 

2352 

14 

X 

15 

1680 

1785 

1890 

1995 

2100 

22J05 

2310 

2520 

14 

X 

16 

1792 

1904 

2016 

2128 

2240 

2352 

2464 

2688 

14 

X 

17 

1904 

2023 

2142 

2261 

2380 

2499 

2618 

2856 

14 

X 

18 

2016 

2142 

2268 

2394 

2520 

2646 

2772 

3024 

14 

X 

19 

2128 

2261 

2394 

2527 

2660 

2793 

2926 

3192 

14 

X 

20 

2240 

23«0 

2520 

2660 

2800 

2940 

3080 

3360 

14 

X 

21 

2352 

2499 

2646 

2793 

2940 

3087 

3234 

3528 

14 

X 

22 

2464 

2618 

2772 

2926 

3080 

3234 

3388 

3696 

14 

X 

23 

2576 

2737 

2898 

3059 

3220 

3381 

3542 

3864 

14 

X 

24 

2688 

2856 

3024 

3192 

3360 

3528 

3696 

4032 

14 

X 

25 

2800 

2975 

3150 

3325 

3500 

3675 

3850 

4200 

14 

X 

26 

2912 

3094 

3276 

3458 

3640 

3822 

4004 

4368 

14 

X 

27 

3024 

3213 

3402 

3591 

3780 

3969 

4158 

4536 

14 

X 

28 

3136 

3332 

3528 

3724 

3920 

4116 

4312 

4704 

15 

X 

15 

1800 

1913 

2025 

2137 

2250 

2363 

2475 

2700 

15 

X 

16 

1920 

2040 

2160 

2280 

2400 

2520 

2640 

2880 

15 

X 

17 

2040 

2168 

2295 

2422 

2550 

2678 

2805 

3060 

15 

X 

18 

2160 

2295 

2430 

2565 

2700 

2835 

2970 

3240 

15 

X 

19 

2280 

2423 

2565 

2707 

2850 

2993 

3135 

3420 

15 

I 

20 

2400 

2550 

2700 

2850 

3000 

3150 

3300 

3600 

MISCELLANEOUS  TABLES 


CUBICAL  CONTENTS  OF  ROOMS 


HAVING    CEILINGS    OF    THE    FOLLOWING    HEIGHTS 


Floor  Area 

8  ft. 

8V6  ft. 

9  ft. 

9%  ft. 

10  ft. 

10%  ft. 

11  ft. 

12  ft. 

15 

I 

21 

2520 

2678 

2835 

2992 

3150 

330& 

3465 

3780 

15 

X 

22 

2640 

2805 

2970 

3135 

3300 

3465 

3630 

3960 

15 

X 

23 

2760 

2933 

3105 

3277 

3450 

3623 

3795 

4140 

15 

X 

24 

2880 

3060 

3240 

3420 

3600 

3780 

3960 

4320 

in 

X 

25 

3000 

3188 

3375 

3562 

3750 

«938 

4123 

4500 

15 

X 

26 

3120 

3315 

3510 

3705 

3900 

4095 

4290 

4680 

15 

X 

27 

3240 

3443 

3645 

3847 

4050 

4253 

4455 

4860 

15 

X 

28 

3360 

3570 

3780 

3990 

4200 

4410 

4620 

5040 

15 

X 

29 

3480 

3698 

3915 

4132 

4350 

4568 

4785 

5220 

15 

X 

30 

3600 

3825 

4050 

4275 

4500 

4725 

4950 

5400 

16 

X 

16 

2048 

2176 

2304 

2432 

2560 

2688 

2816 

3072 

16 

X 

17 

2176 

2312 

2448 

2584 

2726 

2856 

2992 

3264 

16 

X 

18 

2304 

2448 

2592 

2736 

2880 

3024 

3168 

3456 

16 

X 

19 

2432 

2584 

2736 

2888 

3040 

3192 

3344 

3648 

16 

X 

20 

2560  . 

2720 

2880 

3040 

3200 

3360 

3520 

3840 

16 

X 

21 

2688 

2856 

3024 

3192 

3360 

3528 

3696 

4032 

10 

X 

22 

2816 

2992 

3168 

3344 

3520 

3696 

3872 

4224 

16 

X 

23 

2944 

3128 

3312 

3496 

3680 

3864 

4048 

4416 

16 

X 

24 

3072 

3264 

3456 

3648 

3840 

4032 

4224 

4608 

16 

X 

25 

3200 

3400 

3600 

3800 

4000 

4200 

4400 

4800 

16 

X 

26 

3328 

3536 

3744 

3952 

4160 

4368 

4576 

4992 

16 

X 

27 

3456 

3672 

3888 

4104 

4320 

4536 

4752 

5184 

16 

X 

28 

3584 

3808 

4032 

4256 

4480 

4704 

4928 

5376 

16 

X 

29 

3712 

3944 

4176 

4408 

4640 

4872 

5104 

5568 

16 

X 

30 

3840 

4080 

4320 

4560 

4800 

5040 

6280 

5760 

16 

X 

31 

3968 

4216 

4464 

4712 

4960 

5208 

5456 

5952 

16 

X 

32 

4096 

4352 

4806 

4864 

5120 

53T6 

,'5632 

6144 

18 

X 

18 

2592 

2754 

2916 

3078 

3240 

3402 

3564 

3888 

18 

X 

20 

2880 

3060 

3240 

3420 

3600 

3780 

3960 

4320 

18 

X 

22 

3169 

3366 

.3564 

3762 

3960 

4158 

4356 

4752 

18 

X 

24 

3456 

3672 

3888 

4104 

4320 

4536 

4752 

5184 

18 

X 

26 

3744 

3978 

4212 

4446 

4680 

4914 

5148 

5616 

18 

X 

28 

4032, 

4284 

4536 

4788 

5040 

5292 

5544 

6048 

18 

X 

30 

4320 

4590 

4860 

5130 

5400 

5670 

5940 

6480 

18 

X 

32 

4608 

4896 

5184 

5472 

5760 

6048 

6336 

6912 

18 

r 

34 

4896 

5202 

5508 

5814 

6120 

,6426 

6732 

7344 

18 

X 

36 

5184 

5508 

5832 

6156 

6480 

6804 

7128 

7776 

20 

X 

20 

3200 

3400 

3600 

3800 

4000 

4200 

4400 

4800 

20 

X 

22 

3520 

3740 

3960 

4180 

4400 

4620 

4840 

5280 

20 

X 

24 

3840 

4080 

4320 

4560 

4800 

5040 

5280 

5760 

20 

X 

26 

4160 

4420 

4680 

4940 

5200 

5460 

5720 

6240 

20 

X 

28 

4480 

4760 

5040 

5320 

5600 

5880 

6160 

6720 

20 

X 

30 

4800 

5100 

5400 

5700 

COOO 

6300 

6600 

7200 

20 

X 

32 

5120 

5440 

5760 

60SO 

6400 

6720 

7040 

7680 

20 

z 

34 

5440 

5780 

6120 

6460 

6800 

7140 

7480 

8160 

20 

X 

36 

5760 

6120 

6480 

6840 

7210 

7560 

7920 

8640 

20 

X 

38 

6080 

6460 

6840 

7220 

7600 

7980 

8360 

9120 

20 

X 

40 

6400 

6800 

7200 

7600 

8000 

8400 

8800 

9600 

264 


CHAPTER  XX 
RECIPES  AND  MISCELLANEOUS  DATA 

To  Clean  Brass. 

Mix  in  a  stone  jar  one  part  of  nitric  acid,  and  one-half  part 
of  sulphuric  acid.  Dip  the  brasswork  into  this  mixture,  wash 
it  off  with  water,  and  dry  with  sawdust.  If  greasy,  dip  the 
work  into  a  strong  mixture  of  potash,  soda  and  water,  to  re- 
move the  grease,  and  wash  it  off  with  water. 

To  Clean  Zinc. 

Dissolve  a  teaspoonful  of  oxalic  acid  in  a  half  pint  of  water, 
and  wash  the  zinc  with  the  solution,  after  which  the  zinc 
should  be  washed  off  with  water,  and  polished  witha  woolen 
cloth  and  dry  whiting. 

To  Clean  Out  Water  Front  That  is  Filled  With  Rust. 

Take  the  water  front  out  and  place  it  in  a  forge  or  in  a 
furnace,  and  heat  it.  This  will  bake  the  deposit  that  has  col- 
lected in  the  water  front,  and  will  loosen  much  of  it. 

After  being  sufficiently  heated,  it  should  be  removed,  and 
tapped  with  a  hammer  to  dislodge  the  rust  that  clings  to  the 
surface.  In  this  way  the  water  front  may  be  entirely  cleaned. 

To  Remove  Lime  Deposit  in  a  Water  Front. 

After  disconnecting  the  range,  take  out  the  water  front,  and 
immerse  it  in  muriatic  acid,  where  it  should  remain  two  or 
three  hours,  according  to  the  amount  of  deposit  and  the 
strength  of  the  acid.  On  removing  the  water  front  from  the 
acid,  plunge  it  into  water  and  wash  thoroughly. 

Government  Recipe  for  Cleaning  Brass. 

The  following  is  said  to  be  the  method  used  in  government 
arsenals  for  cleaning  brass.  Use  two  parts  of  common  nitric 
acid  to  one  part  of  sulphuric  acid.  The  acid  should  be  kept 
in  a  stone  jar.  Articles  that  are  to  be  cleaned  should  be  first 
dipped  into  the  acid,  then  into  clear  water,  and  then  dried 
with  sawdust.  This  cleaning  process  will  change  the  brass 
at  once  to  a  brilliant  color.  If  the  metal  to  be  cleaned  is 


RECIPES  265 

greasy,  the  grease  should  be  first  removed,  by  dipping  the 
article  in  a  strong  solution  of  potash  and  soda  in  warm  water. 

To  Prevent  Rusting  of  Iron  and  Steel. 

Cover  the  surface  with  a  mixture  made  of  I  Ib.  melted  lard, 
I  oz.  camphor,  and  black  lead  to  give  it  the  desired  color. 
By  covering  the  surface  with  this  mixture,  the  metal  will  be 
protected  for  an  indefinite  length  of  time,  and  it  may  be 
cleaned  off  with  naptha  or  benzine. 

To  Prevent  Polished  Iron  From  Rusting. 

Cut  a  small  amount  of  beeswax  with  benzine,  and  supply 
it  to  the  surface  of  the  polished  iron.  This  has  long  been  in 
use  in  protecting  Russia  iron  through  the  damp  season,  and 
has  been  found  very  effective. 

To  Clean  Zinc. 

Zinc  is  generally  cleaned  by  scouring  it  with  fine  sand  and 
pumice.  A  bath  of  two  parts  of  nitric  acid,  and  one  part 
sulphuric  acid  will  also  give  results.  The  bath  should  be 
followed  by  a  water  bath. 

After  cleaning  zinc,  a  permanent  bright  surface  may  be 
obtained  by  giving  it  a  coat  of  transparent  varnish. 

How  to  Clean  Steel  Tapes. 

Cover  the  tape  with  crude  oil  and  rub  down  with  No.  O 
steel  wool.  This  will  clean  the  rust  from  the  tape  without 
injury  to  the  etching.  If  the  tape  is  not  very  rusty  it  may 
be  brightened  up  by  rubbing  with  powdered  pumice  or  dry 
cement. 

To  Paint  Galvanized  Iron. 

There  is  very  often  difficulty  in  making  paint  stick  to  gal- 
vanized iron.  The  galvanized  iron  should  first  be  cleaned 
with  a  solution  of  ammonia  and  water.  When  the  iron  has 
dried  off,  it  is  ready  for  the  paint,  which  will  then  adhere 
without  any  difficulty. 

To  Keep  Plaster  of  Paris  From  Setting  Too  Quickly. 

Sift  the  plaster  into  the  water,  allowing  it  to  soak  up  the 
water,  without  stirring,  which  would  admit  air  and  cause 
the  plaster  to  set  quickly.  If  desired  to  keep  the  plaster 
soft  for  a  much  longer  time,  add  to  every  quart  of  water, 
one-half  teaspoonful  of  common  cooking  soda.  This  will  gain 
all  the  time  necessary. 


266  RECIPES 

To  Solder  Galvanized  Iron. 

Be  sure  to  have  a  very  hot  soldering  copper  in  soldering 
galvanized  iron,  even  though  it  has  to  be  returned  often. 
When  the  copper  is  not  sufficiently  hot,  it  simply  solders  to 
the  surface  of  the  zinc,  which  is  liable  to  peel  off.  In  having 
the  iron  hot,  the  soldering  gets  to  the  iron,  and  the  solder 
and  zinc  are  more  thoroughly  fused  together  and  to  the  iron. 

A  Flux  for  Tin  Roofing. 

A  good  roofing  flux  is  made  of  two  parts  of  binnacle  oil, 
and  one  part  of  rosin.  Rosin,  cut  with  alcohol,  and  applied 
with  a  swab,  also  is  very  satisfactory. 

Fluxes  for  Various  Metals. 

For  cast  and  malleable  iron  and  steel,  borax  and  sal-am- 
moniac. For  brass,  gun  metal  and  copper,  chloride  of  zinc, 
sal-ammoniac  or  rosin.  For  zinc,  chloride  of  zinc.  For  tinned 
iron,  chloride  of  zinc  or  rosin.  For  lead,  tallow  for  coarse 
solder,  and  rosin  for  fine  solder.  For  pewter,  gallipoli  oil. 

To  Keep  Soldering  Coppers  in  Order  While  Soldering  With 

Acid. 

In  a  pint  of  water  dissolve  a  piece  of  sal-ammoniac  about 
the  size  of  a  walnut.  Whenever  the  copper  is  taken  from  the 
fire,  dip  the  point  into  the  liquid,  and  the  zinc  taken  from  the 
acid  will  run  to  the  point  of  the  copper  and  can  then  be  shaken 
off,  leaving  the  copper  bright. 

A  Good  Soldering  Acid. 

In  i  Ib.  muriatic  acid,  dissolve  all  the  zinc  it  will  take  up, 
thereby  forming  zinc  chloride.  Add  to  the  zinc  chloride  I 
ounce  of  sal-ammoniac.  Reduce  with  the  same  amount  of 
water  there  is  of  the  acid. 

A  Non-Corrosive  Soldering  Paste. 

An  excellent  paste  for  soldering  purposes  can  be  made  of 
one  part  by  weight,  of  chloride  of  zinc,  and  sixteen  parts  of 
some  such  grease  as  vaseline,  thoroughly  mixed  together. 
The  chloride  of  zinc  is  known  to  every  tinsmith,  and  is  made 
by  dissolving  in  muriatic  acid,  as  much  zinc  as  the  acid  will 
eat  up. 


RECIPES  267 

Waterproof  Glue. 

Use  one  part  India  rubber,  and  three  parts  gum  shellac, 
by  weight. 

Dissolve  each  in  separate  vessels,  in  ether,  and  under  a 
mild  heat. 

After  being  completely  dissolved,  mix  the  two,  and  keep 
in  an  air-tight  vessel.  This  mixture  will  withstand  both  hot 
and  cold  water,  and  nearly  all  kinds  of  acids. 

Common  glue,  mixed  with  varnish  or  linseed  oil,  applied 
to  the  parts  to  be  glued  after  they  have  been  warmed,  will 
be  permanent  and  with  stand  water. 

How  to  Make  Putty. 

Mix  dry  whiting  with  raw  linseed  oil.  For  glazing,  add 
about  10  per  cent,  of  white  lead  to  increase  durability.  In 
hot  climates  a  little  cottonseed  oil  should  be  added  to  prevent 
the  putty  from  drying  too  quickly. 

Fireproof  Cement  for  Furnaces. 

A  cement  or  mortar  that  will  close  up  cracks  in  furnaces 
to  keep  the  gas  from  escaping  can  be  made  as  follows:  Mix 
together  seventy-five  parts  of  wet  fire  clay,  three  parts  of 
black  oride  manganese,  three  parts  of  white  sand  and  one  part 
of  powdered  asbestos.  Thoroughly  mix  by  adding  enough 
water  to  make  a  smooth  paste.  Apply  over  the  cracks  and 
when  dry  it  will  be  as  hard  as  iron  and  stick  like  glue. 

Rust  Joints. 

To  make  a  good  rust  joint,  use  5  Ibs.  iron  filings,  and  I  oz. 
each  of  sal-ammoniac  and  flour  of  sulphur.  Do  not  use  a 
greater  amount  of  sal-ammoniac  as  it  is  likely  to  generate 
heat,  and  thereby  cause  expansion.  A  stronger  but  slower 
setting  cement  may  be  made  by  using  the  following  propor- 
tions of  ingredients:  12  Ibs.  iron  filings,  2  ozs.  sal-ammoniac, 
and  i  oz.  flour  of  sulphur. 

Friction  of  Water  in  Passing  Through  Pipes. 

Friction  of  Water  in  pipes  is  approximately  equal  to  the 
square  of  the  velocity  at  which  it  is  flowing. 

Therefore  the  greater  the  velocity,  the  greater  the  friction 
will  be.  The  friction  of  water  in  passing  a  90  degree  bend  is 
as  great  as  the  friction  of  a  length  of  such  pipe  38  times  as 
great  as  the  diameter.  The  friction  of  water  in  small  pipes  is 
much  greater  than  in  large  pipes,  as  in  the  small  pipe  a  much 
larger  proportion  of  the  water  comes  in  contact  with  the  sides 
of  the  pipe. 


268  RECIPES 

Heating  Capacity  of  Stove  and  Furnace  Coils. 

When  a  stove  or  furnace  heating  coil  is  so  placed  as  to  be 
covered  by  the  fire,  it  is  estimated  that  it  will  take  about  one 
square  foot  of  heating  surface  in  the  coil  to  heat  fifteen  gallons 
of  water  in  the  boiler. 

If  the  coil  is  to  be  of  J4  inch  pipe,  it  will  require  45  inches 
of  pipe  for  each  15  gallons  of  tank  capacity.  If  a  I  inch  coil 
is  to  be  used,  it  will  require  3  feet  of  pipe  for  15  gallons. 

In  the  case  of  furnace  coils  that  are  placed  in  the  combus- 
tion chamber,  above  the  fire,  the  heating  power  of  the  coil 
will  not  be  so  great,  for  the  reason  that  when  the  feed  door 
is  opened,  or  fresh  coal  is  thrown  onto  the  fire,  the  heating 
of  the  coil  is  checked.  Under  these  circumstances  it  would 
not  generally  be  safe  to  figure  on  heating  much  over  10  gal- 
lons per  square  foot  of  heating  surface. 


INDEX  I 

Furnace  Heating 


Air,  Amount  Required  for  Ventilation Ill 

Air,  Amount  Moved  by  Fan 115 

Air,  Composition  of 109 

Air  Filter 55 

Air  Moistening  and  Humidity   121 

Air  Moistening,  Investigation  of  Results  Obtained 124 

Air  Moistening,  Methods  of 125-129 

Air  Moistening,  Methods  of  Testing 129 

Air  Moistening,   Reduction   of   Fuel 123 

Air,  Recirculation  of 132 

Air,  Vitiation  of no 

Apparatus  for  Controlling  Drafts 161 

Application   of   Heating   Rules 80 

Appliances    for   Fuel    Saving 147 

Area  and  Height  of  Chimney  Flue  12-14 

Area  of  Cold  Air  Duct 32,  33 

Automatic  Air  Damper 82,  83,  84 

Automatic  Draft    Regulators 159 

Auxiliary  Heaters,  Types  of 140 

Auxiliary  Heating,  Arrangement  of 141-143 

Auxiliary  Heating  from  Furnaces 138 

Auxiliary  Heating,  Methods  of 139-145 

Auxiliary  Heating,  Methods  of  Installation   144 

Bends 100 

Black  Sheets,  Weights  of 239 

Boiling  Point  of  Fluids 249 

Brass,  Government  Recipe  for  Cleaning 264 

Brass,  To   Clean 264 

Capacity  of  Exhaust  Fans 1 18 

Carbonic  Acid  Gas,  Parts  in  the  Air 109,  in 

Casing  and  Top  of  Furnace 24-  26,  98 

Cement  Construction,  Determining  Quantities 176 


270  FURNACE  HEATING 

Cement  Construction  for  Furnace  Men 173 

Cement  Construction,  Methods  Used 177 

Cement  Construction,  Tools  Required 175 

Cement  for  Furnaces,  Fire-Proof 267 

Character  and  Size  of  Chimney  Flue 9 

Character  and  Size  of  Furnace 23,  24 

Chimney  Flue 9 

Chimney  Flue,  Area  and  Height 12,  14 

Chimney  Flue,  Character  and  Size 9 

Chimney  Flue,  Construction    10,  1 1,  12 

Chimney  Flue,  Draft    Gauge 15,  16 

Chimney    Flues,  Location 17,  18 

Chimney  Flues,  Sources  of  Trouble 18,  19 

Chimney  Flues,  Table  of  Sizes 17 

Chimney  Flue,  Table  of  Velocities 16 

Chimney  Flue,  Tests  of 15,  17 

Chimney  Flue    Troubles    19,  20 

Circle,  Areas  of 256 

Circle,  Circumferences  of 256 

Circle,  Rules  Relative  to   -. 257 

Coal,  Composition  of   165 

Coal,  The  Universal  Fuel 171 

Coke    Air  Moistener 125 

Coke,  How  Produced 165 

Cold  Air,  Methods  of  Supplying 29 

Cold  Air    Duct,  Area  of 32,  33 

Cold  Air  Filter   31 

Cold  Air  Pit  for  Furnace 27 

Cold  Air  Supply   for  Furnaces 29,  33 

Combustion  of  Fuel 163 

Composition  of  Air 109 

Composition  of  Coal    165 

Concrete  Mixtures    173 

Conductors,  Table  of  Sizes 251 

Construction  of  Chimney  Flue 10,  1 1,  12 

Construction,  Practical  Methods  of 85 

Correct  Tests  of  Chimney  Flue IS"1/ 

Cost  of  Hard  Firing   101 

Cost  of  Heat  Regulation 156 


FURNACE  HEATING  271 

Cubical  Contents  of  Rooms 258-263 

Draft  Gauge  for  Testing  Chimney  Flue 15,  16 

Draft  Regulators 159 

Ducts  for  Recirculation  of  Air,  Method  of  Connecting. . .  136 

Dust  Discharge   97 

Effect  of  High  Winds 135 

Efficiency  of  Exhaust  Fans 117 

Estimate,  Form  for 77,  78 

Estimating  Furnace  Work 70,  77,  79 

Estimating  Sizes  of  Pipe 47 

Example  of  Good  Furnace  Work 103,  107 

Exhaust  Fans,  Efficiency  of 117 

Exhaust  Fans,  Horse  Power  Required 1 18 

Exhaust  Fans,  Speed  and  Capacity 1 18 

Exhaust  Fans,  Table  of  Capacities 119 

Expansion  Tank,  Size  and  Location 144 

Factors  of  Good  Furnace  Work 97 

Fan-Blast  Heating    61 

Fan-Blast  Heating  with  Trunk  Line  Piping 65 

Filter  for  Cold  Air 31 

Filtering    Chamber 55 

Fittings  for  Furnace  Heating  37,  38 

Flues,  Location  of 42 

Fluids,  Boiling  Points  of 249 

Fractions  and  Decimals 255 

Fuel    163 

Fuel,  Air  Required  for  Combustion 166 

Fuel,  Analysis  of   165 

Fuel,  Chemical  Components  and  Combustion 163 

Fuel    Saving  Devices 146 

Furnace,  Auxiliary  Heating  from 138 

Furnace    Casing  and  Top 24,  26,  98 

Furnace,  Character  and  Size 23,  24 

Furnace,  Coil  in  Fire  Pot 139 

Furnace    Coils,  Heating  Capacity  of s 268 

Furnace,  Cold  Air  Pit 27 

Furnace,  Cold  Air  Supply  29,  33 

Furnace    Fittings    37,  38 

Furnace,  Foundation  for 97 


272  FURNACE  HEATING 

Furnace   Heating,  Arguments  for 22,  23 

Furnace,  Heating    Surface 101 

Furnace   Heating,   History  of 21 

Furnace,  Installation  of 44 

Furnace,  Location  of 26 

Furnace,  Methods  of  Setting 26,  30 

Furnace    Pipe 36,  37,  99 

Furnace    Ratings    34,  35 

Furnace,  Size   Required    33~35 

Furnace,  The  21 

Furnace    Work,  Estimating    70 

Furnace    Work,  Factors  of  Good  97 

Furnace    Work,  Importance  of  High  Class IO2 

Galvanized  Iron,  to  Solder 266 

Galvanized  Iron,  to  Paint  265 

Galvanized  Pipe  and  Elbows,  Weights  of 242 

Galvanized  Sheets,  Gauges  and  Weights 240 

Glue,  Water  Proof 267 

Grates,  Diameter  of  251 

Grates,  Square  Feet  of  Surface 251 

Heater  Pipes,  Stock  Sizes  of  Tin  for 244 

Heating,  Fan-Blast  61 

Heating    Rules,  Intelligent  Application  of 80 

Heating,  Trunk  Line 57 

Heat  Regulation,  Cost  of 156 

Herr  Humidifier  126 

High  Class  Work,  Importance  of IO2 

History  of  Furnace  Heating 21 

Horse  Power  Required  for  Exhaust  Fans Il8 

Humidity  and  Air  Moistening 121 

Hygrometer,  The 129 

Importance  of  High  Class  Furnace  Work IO2 

Installation  of  the  Furnace 44 

Iron,  to  Prevent  Rusting 265 

Location  for  Rotating  Register ioo 

Location  of  Chimney  Flue 17,  18 

Location  of  Furnace 26 

Location  of  Registers 40,  41 

Melting  Points  of  Metals. -. 249 


FURNACE  HEATING  273 

Metals,  Fluxes  for  266 

Metals,    Melting  Points  of 249 

Method  of  Estimating  Furnace  Work 70 

Methods  of  Setting  Furnace 26,  30 

Methods  of  Ventilating ill 

Millimeters  and  Decimals 253 

Miscellaneous  Data  and  Recipes   264-268 

Mixing  Concrete  174 

Opposition  to  Re-circulation  of  Air 134 

Origin  of  Thermostats 148 

Plaster  of  Paris,  To  keep  from  Setting 265 

Practical  Methods  of  Construction 85 

Propeller  Fan,  Use  for  Ventilation 114 

Putty,  How  to  Make 267 

Radiator,  Size  of 138 

Ratings  of  Furnaces 34,  35 

Recipes  and  Miscellaneous  Data   264-268 

Re-circulation  of  Air 132 

Re-circulation  of  Air,  Method  of  Connecting  Ducts  for.        136 

Rectangular  Tanks,  Capacities  in  U.  S.  Gallons 245 

Registers,  Dimensions  oi  ...._, 250 

Registers,  Location  of 40,  41 

Registers,  Side  Wall 38,  39 

Registers,  Size  of 42,  43 

Registers,  Table  of  Standard  Sizes 250 

Regulators,  Electric    149 

Regulators,  How  to  Attach 156 

Regulators,  Non-Electric    150 

Rooms,  Cubical  Contents  of 258-263 

Rotating  Register,  Location  of 100 

Round  Tanks,  Capacities  in  Gallons   246 

Rules,  Tables  and  Information   237 

Rust  Joints,  How  to  Make 267 

School  House  Warming  and  Ventilating 91 

Sheet  Copper,  Weights  and  Thickness   . : 241 

Sheet  Zinc,  Weight  of   242 

Side  Wall  Registers  38,  39 

Size  of  Furnace  Required   33,  35 

Size  of  Registers   42,  43 


274                                FURNACE  HEATING  r 

Size  of  Warm  Air  Pipes 40 

Soldering  Acid    266 

Soldering  Coppers.  To  Keep  in  Order 266 

Soldering    Paste    266 

Speed  of  Exhaust  Fans    118 

Stack   for  Ventilating    1 12,  1 13 

Standing  Seam  Roofing,  Table  of  Costs  243 

Standing  Seam  Roofing;  Tin  Required 244 

Steel  Sheets,  Weights  of 238 

Steel  Tapes,  To  Clean    265 

Steel,   To   Prevent  Rusting    265 

Stove  Coils,  Heating  Capacity  of 268 

TABLES  : 

Air  Moved  by  Propeller  Fan 115 

Areas  and  Circumferences  of  Circles 256 

Cost  for  Standing  Seam  Roofing 243 

Diameters  of  Wire    247-248 

Gallons  in  Round  Tanks  246 

Gauges  and  Weights  of  Black  Sheets 239 

Gauges  and  Weights  of  Galvanized  Sheets 240 

Horse  Power  of  Belting 254 

Exposures  74 

Common  Fractions  and  Decimals 255 

Millimeters  and  Decimals 253 

Chimney  Flues,  Sizes 17 

Pipes,  Flues  and  Registers,  Sizes 74 

Weights  and  Measures    252 

Size  of  Conductors  251 

Size  of  Registers 43 

Stock  Sizes  Tin  for  Heater  Pipes 244 

Tin  Required  for  Standing  Seam  Roofing 244 

U.  S.  Gallons  in  Rectangular  Tanks 245 

Weights  of  Copper  Sheets   241 

Weights  of  Galvanized  Pipe  and  Elbows 242 

Weights  of  Sheet  Zinc    242 

Weights  of  Steel 238 

Weight  of  Tin  Plates 243 

Weight,  Strength  and  Size  of  Wire 249 

Wire,  Diameters  of   247-248 


FURNACE  HEATING  275 

Tanks,  Capacity  in  Gallons  and  Barrels 253 

Temperature  Regulation   146 

Temperature  Regulation,  Cost  of   156 

Temperature  Regulation,  Electric  Regulators    149 

Temperature   Regulation,    Non-Electric   Regulators 150 

Temperature  Regulation,  Value  of   154 

Thermostats,  How  to  Sell 155 

Thermostats,  Method  of  Attaching 156 

Thermostats,  Origin  of   148 

Tin  Plates,  Weight  Per  Box   243 

Tin  Roofing,  Flux  for 266 

Trunk  Line  Heating   57 

Velocity  in  Chimney  Flues  16 

Ventilation    22,  23,  108 

Ventilation  by  Use  of  Propeller  Fan   144 

Ventilation,  Fresh  Air  Required   in 

Ventilation,  Methods  of 1 1 1 

Ventilating  Stack    1 12,  1 13 

Warm  Air  Pipes,  Size  of   40 

Warming  and  Ventilating  School  Houses   91 

Water,  Friction  in  Passing  through  Pipes  267 

Water  Front,  to  Clean  Out  Rust   264 

Water  Front,  to  Remove  Lime  Deposit 264 

Weights  and  Measures,  Table  of   252 

Weights  of  Black  Sheets   239 

Weights  of  Galvanized  Pipe  and  Elbows 242 

Weights  of  Galvanized  Sheets    240 

Weights  of  Sheet  Copper    241 

Weights  of  Sheet  Zinc   242 

Weights  of  Steel    238 

Weight  of  Tin  Plates  per  Box 243 

Wire,  Diameters  of   247,  248 

Wire,  Weight,  Strength  and  Size 249 

Zinc,  To  Clean 264,  265 


INDEX  II 

Furnace  Fittings 


Adjustable  Elbows,  Positions  for  Setting 186 

Air  Tight  Joints  in  Wall  Pipes 217 

Angle  of  Collar  Determined  by  Deflector 179 

Angles  in  Warm  Air  Elbows,  Methods  of  Finding. . .  .232-236 

Area  in  Wall  Pipes,  How  it  is  Decreased 217 

Areas  of  Round  Pipes  and  Registers,  Table  of 203 

Asbestos  Covering  in  Wall  Pipe,  Protecting 217 

Bonnet  and  Deflector 179 

Bonnets  or  Hoods,  Conical 179 

Boots,  Offset 21 i -216 

Boots  or  Wall  Pipe  Starters  207 

Box-Shaped  Starter  Connecting  Two  Registers 207 

Box-Shaped  Starters,  Nine  Styles  of   208 

Casings,   Furnace    180,  181 

Casing  Rings,  Spacing - 180 

Cast  Iron  Shoe  for  Cold  Air  Connection 199 

Circular  Joints,  Locking  , . . .  189 

Circular  Joints,  Seaming 188 

Cold  Air  Duct  Elbows,  Finding  True  Angles  in 231 

Cold  Air  Duct  Elbows,  Frictionless  201 

Cold  Air  Duct  Elbows,  Seaming  202 

Cold  Air  Shoe  Connection,  Cast  Iron  for 199 

Cold  Air  Shoe  for  Inside  Air  Connection 198 

Cold  Air  Shoes 196 

Collars  Joining  a  Flat  Top  Casing 180 

Collar  on  Pitched  Bonnet   181 

Collar  on  Straight  Bonnet   184 

Collar  to  Register  Box,  Joining  204 

Collars,  Various  Styles  of  181 

Collar  Joining  a  Straight  Bonnet  180 

Combination  Header  on  Register  Box 206 

Compound  Wall  Pipe  Offsets  220222 


FURNACE  FITTINGS  277 

Conical  Bonnets  or  Hoods 179 

Connecting  Sheet  Metal  Shoe  Casing   199 

Connecting  Shoes  to  Center  of  Furnace  198 

Connecting  Shoes  to  Round  Cold  Air  Pipes 197 

Covering  Wall  Pipes  with  Paper  217 

Deflector  on  Conical  Bonnet   179 

Degree  of  Miter  Line  for  Four-Piece  Elbow 187 

Determining  Size  of  Register  Box 203 

Diameter  of  Main  Pipe,  Determining  Unknown 224 

Double  Offset   220,  222 

Double  Wall   Pipes 218 

Elbow,  Frictionless  Cold  Air  Duct 201 

Elbow,  Oval,  on  the  Flat  189 

Elbow,  Oval,  Three-Piece  on  the  Sharp   189 

Elbow  Patterns,  Methods  Employed   232 

Elbow,    Reducing    190 

Elbows   185,  186,  187 

Elbows,  Cold  Air  Duct,  Finding  True  Angles  in 231 

Elbows  Less  Than  Right  Angles 188 

Elbows,   Oval    188 

Elbows,  True  Angles  in,  Finding 232-236 

Equal  Fork  in  Trunk  Line  Fitting 224 

Fastening  Collar  to  Straight  Bonnet   184 

Finding  True  Angles  in  Cold  Air  Duct  Elbows 231 

Finished  Collar  for  Flat  Casing  Top 185 

Finished  Collar  for  Pitched  Bonnet   185 

Fittings  for  Trunk  Line  Heating  Systems 223 

Fittings  Used  in  Furnace  Piping  218 

Flat  Casing  Top,  Finished  Collar  for 185 

Flat  Top  Casing,  Collars  Joining   180 

Floor  Register  Box  in  Four  Pieces  204 

Floor  Register  Box  in  One  Piece 204 

Floor  Register  Boxes    203 

Flues,  Metal,  in  Brick  Walls 218 

Fork,  Equal,  in  Trunk  Line  Fitting 224 

Fork  of  Equal  Prongs  in  Trunk  Line  System 225 

Fork,  Unequal,  in  Trunk  Line  Fittings   226 

Forks  for  Trunk  Line  Systems   224-231 

Four-Piece  90  Degrees  Elbow,  Rule  for 186 


278  FURNACE  FITTINGS 

Frictionless  Cold  Air  Duct  Elbows   201 

Frictionless  Starters  207-212 

Furnace  Casings    181 

Furnace  Fittings,  Single  Wall,  Twenty-Six  Styles  of...  219 

Furnace  Piping,  Fittings  Used  in   218 

Header,  Combination,  on  Register  Box   206 

Header,    Round    193 

Joining  Collar  to  Register  Box  204 

Locking   Circular   Joints    189 

Metal  Flues  in  Brick  Walls   218 

Methods  of  Finding  True  Angles  in  Cold  Air  Elbows.  .  .232-236 

Miter  Line  for  Four-Piece  Elbow,  Finding  Degree  of.  187 

Obtaining  Radii  for  Curves   201 

Offset   Boots    211-216 

Offset,  Double 220,  222 

Oval  Elbow  on  the  Sharp,  Three-Piece    189 

Oval  Elbows    188 

Pitched  Bonnet,  Collar  for  181,  185 

Positions  for  Setting  Four-Piece  Adjustable  Elbow 186 

Pronged  Fork,  Three  Equal  in  Trunk  Line  System 228,  230 

Pronged  Fork,  Three  Unequal  in  Trunk  Line  System...  229 

Protecting  Asbestos  Covering  in  Wall  Pipe   217 

Radii  for  Curves,  Rule  for  Obtaining 201 

Reducing  Elbow    190 

Reducing  Joint,  Short  Rule  for   » . .  223 

Reducing  T,   Riveting   197 

Reducing   T-Joint    195 

Register  Box,  Determining  Size  of 203 

Register  Box,  Floor,  in  One  Piece   204 

Register  Box,  Floor,  in  Four  Pieces 204 

Register  Boxes 206 

Risers,  Wall  Pipes  or   217 

Riveted  Joints  in  Tees   196 

Riveting  Reducing  T   197 

Round    Header    « 193 

Round  Pipes  and  Registers,  Table  of 203 

Round  to  Oval  Frictionless  Starter 207 

Rule  for  Developing  Four-Pieced  90  Degree  Elbow 186 

Rule  for  Reducing  Joint     223 


FURNACE  FITTINGS  279 

Seaming  Circular  Joints  188 

Seaming  Cold  Air  Duct  Elbows  202 

Setting  Four-Piece  Adjustable  Elbows  186 

Shoe,  Cast  Iron,  for  Cold  Air  Connection  199 

Shoe,  Cold  Air,  for  Inside  Air  Connection 198 

Shoe  Connecting  to  One  Side  of  Furnace 19^) 

Shoe,  Sheet  Metal  for  Rectangular  Pipe 198 

Shoes,  Cold  Air  196-201 

Shoes,  Connecting  to  Furnace  Casing  199 

Shoes,  Connecting  to  Center  of  Furnace 198 

Shoes  for  Round  Cold  Air  Pipes,  Connecting 197-198 

Short  Rule  for  Reducing  Joint  223 

Single  Wall  Furnace  Fittings,  Twenty-Six  Styles  of. .  219 

Straight  Bonnet,  Collar  on  184 

Spacing  the  Casing  Rings  180 

Starter,  Box  Shaped,  Connecting  Two  Registers 207 

Straight  Bonnet,  Collars  Joining  180 

Straight  Bonnet,  Fastening  Collar  on 184 

T-Joint  Between  Pipes  of  Equal  Diameter 192 

T- Joint  Between  Pipes  of  Unequal  Diameter 193,  194 

T-Joint,  Reducing  195 

Table  of  Areas  of  Round  Pipes  and  Registers 2*03 

Tees,  Riveted  Joints  in  196 

Three  Equal  Pronged  Fork  in  Trunk  Line  System 228 

Three-Piece  Oval  Elbow  on  the  Flat 189 

Three-Piece  Oval  Elbow  on  the  Sharp 189 

True  Angles  in  Cold  Air  Duct  Elbows,  Finding 231 

True  Angles  in  Warm  Air  Elbows,  Finding 232-236 

True  Angles  in  Warm  Air  Elbows,  Finding  with  Line 

and  Bevel  235 

Trunk  Line  Fittings,  Equal  Fork  in 224 

Trunk  Line  Fittings,  Unequal  Fork  in 226 

Trunk  Line  Heating  Systems,  Fittings  for 223 

Two-Pronged  Fork  for  Trunk  Line  System 225 

Two-Pronged  Fork,  Unequal,  Determining  the  Unknown 

Diameter  in  • 227 

Unequal  Fork  in  Trunk  Line  Fittings  226 

Unequal  Three-Pronged  Fork  in  Trunk  Line  System.  . . .  229 

Unknown  Diameter  of  Main  Pipe,  Determining 224 


280  FURNACE  FITTINGS 

Wall  Pipe  Offsets,  Compound 220-222 

Wall  Pipe  Starters  207 

Wall  Pipes,  Covering  with  Paper  217 

Wall  Pipes,  How  Area  is  Decreased  in 217 

Wall  Pipes  or  Risers   217 

Wall  Pipes,  Securing  Air  Tight  Joints  in 217 


SHEET  METAL 

PUBLISHED    MONTHLY 


A  specialised  journal,  accepted  and  approved  as  the  authorita- 
tive organ  of  its  field  in  which  it  enjoys  a  universal  circulation. 
It  deals  exclusively  with  the  various  branches  of  modern  sheet 
metal  work,  including  the  mechanical  and  business  problems  of 
the  trade. 

It  is  a  superior  magazine  presenting  an  unequalled  variety  and 
quality  of  reading  matter  for  sheet  metal  workers,  each  number 
containing  interesting  and  valuable  expositions  of  modern 
methods.  Briefly  stated,  there  are  included  among  the  leading 
subjects  considered: 

Constructive  Practice  in  the  Various  Departments  of  Sheet 
Metal  Work. 

Cornice  and  Skylight  Making,  Metal  Roofing. 

The  Construction  and  Installation  of  Heating,  Ventilating, 
Blower  and  Exhaust  Systems. 

Expert  Demonstrations  of  Problems  in  Pattern  Cutting. 
The  Plainest  and  Most  Practical  Articles  on  Warm  Air  Fur- 
nace Heating. 

These  Practical  Discussions  are  Supplemented  by  the  Latest 
Sheet  Metal  Trade  News,  Market  Reports,  and  Reliable  Current 
Price  Lists  of  Materials. 

SHEET  METAL  is  Designed  for  Practical  Purposes  in  the  Office, 
the  Shop  and  (or  Home  Reference  and  Study. 

ONE    DOLLAR   A   YEAR 


SHEET  METAL  PUBLICATION  COMPANY 

Tribune  Building,  New  York. 


Practical  Exhaust  and  Blow  Piping 

A  Treatise  of  the  Planning:  and  Installation  of 
Fan  Piping  in  all  its  Branches 


BY  WILLIAM  H.  HAYES. 

At  the  present  time  no  depart- 
ment of  sheet  metal  work  offers  a 
more  profitable  field  of  opportunity 
for  sheet  metal  workers  than  ex- 
haust and  blow  pipe  work.  Every 
operator  should  be  qualified  with  a 
practical  knowledge  of  the  correct 
design  and  installation  of  fan  pip- 
ing systems. 

This  book  was  written  by  an  ex- 
pert of  long  and  varied  experience 
in  the  field  as  a  foreman  and  super- 
intendent and  the  treatment  is  based 
on  practical  daily  work.  It  is  re- 
liable, easily  understood  and  ap- 
plied, covering  the  essentials  of 
efficient  construction  very  clearly. 

Contains  Sixteen  Sections 

Each  treating  a  leading  department  of  blower  work  and  compre- 
hending specific  information  of  construction,  installation  and  cost. 

General  Rules. 

Connecting  Dust  Separator  and  Feeder. 
Piping  for  Automatic  Firing  System  of  Boilers. 
Constructing  the  Feeder  Nozzle  and  Switch. 
Piping  System  for  a  Planing  Mill. 
Pipe  Connections  for  a  Flooring  Machine. 
Designs  for  Hoods  and  Sweepers. 
Hoods  for  Special  Machines. 
Proper  Construction  of  the  Separator. 
Efficiency  of  the  Exhaust  Fan. 

Use  of  the  Two-Way  Mixing  Valve  and  the  Automatic  Damper. 
Piping  a  Forge  Shop,  including  the  Blast  and  Suction  Systems. 
"Don'ts"  and  "Don't  Forgets"  for  Blow  Pipe  Men. 
Correspondence  Relating  to  Special  Problems. 
Hints   on   Installing  an   Exhaust   System. 
Hints  on  Estimating  the  Cost  of  an  Exhaust  System. 

Comprising    160   pages,    51    illustrations.      Printed   on   heavy 
paper,  durably  bound  in  cloth Price,  $2.00 


SHEET  METAL  PUBLICATION  COMPANY 

Tribune  Building,  New  York 


Practical 

Sheet  Metal  Work  and 
Demonstrated  Patterns 


.     O  G 
H  U 


I    E   *   E 

3  R  w  w 


L&X    ' 

f    T  V 

*     I  Y    L   P 

6    N  „ .  E    R 

H  S  J 

T  H  n 

I   °  A 

>   p  A 

w  v 

o  b     L 

R  R 

K  K 


Here  is  comprised  a  sheet 
metal  workers  library  in  12 
large  volumes.  Each  volume  is 
devoted  to  pattern  cutting,  shop 
and  erection  methods  as  applied 
to  a  given  branch  of  the  trade, 
all  being  well  classified  and  in- 
dexed for  ready  reference. 

The  methods  are  the  out- 
growth of  actual  practice  and  the 
patterns  are  among  the  most 
practical  and  useful  in  print.  The 
text  is  very  freely  illustrated,  up- 
ward of  2,500  engravings  being 
contained  in  the  series.  As  aids 
to  rapid  and  accurate  work,  this 
entire  set  of  books  or  selections 
of  the  volumes  will  prove  an  in- 
valuable possession  to  the  oper- 
ator. 
LIST  OF  VOLUMES. 

I— Leaders  and  Leader  Heads — 113  pages,  150  figures. 

2 — Gutters  and  Roof  Outlets — 116  pages,   194  figures. 

3 — Roofing — 138  pages,  207  figures. 

4 — Ridging  and  Corrugated  Iron  Work — 132  pages,  239  figures. 

5 — Cornice  Patterns — 119   pages,    195   figures. 

6 — Circular  Cornice  Work — 126  pages,  194  figures. 

7 — Practical  Cornice  Work — 139  pages,  237  figures. 

8 — Skylights — 122  pages,  260  figures. 

9 — Furnace  and  Tin  Shop  Work — 145  pages,  239  figures. 
10 — Piping  and  Heavy  Metal  Work — 144  pages,  259  figures. 
ii— Automobile  and  Sheet  Metal  Boats — 137  pages,   193  figures. 
12 — Special  Problems — 144  pages,  150  figures. 

Size  of  volumes,  11x8^2  inches.  Substantially  bound  in  cloth. 

Price  of  Set  (Twelve  Volumes).  $15.00. 
Price  of  Single  or  Selected  Volumes,  each,  $1.50 

SHEET  METAL  PUBLICATION  COMPANY 

Tribune  Building,  New  York 


New  Metal  Worker  Pattern  Book 

A  Treatise  on  the  Principles  and  Practice 

of  Pattern  Cutting  as  Applied  to  All 

Branches  of  Sheet  Metal  Work 

By  GEORGE  W.  KITTREDGE 

A   LARGE   QUARTO    VOLUME 
Containing  744  Illustrations  and  Diagrams 

This  is  the  universally  used  compendium  of  sheet  metal 
pattern  problems.  It  may  be  consulted  for  guidance  in  laying 
out  every  form  of  work  that  comes  up  in  the  shop,  demonstrating 

as  it  does,  218  distinct  problems 
covering  every  example  of  work  of 
probable  occurrence,  or  related  ex- 
amples in  which  their  principles  are 
involved.  Hence  it  may  be  said  that 
all  forms  of  work  are  here  compre- 
hended in  the  pattern  problems  sec- 
tion,, from  pages  96  to  429. 

The  preliminary  chapters  com- 
prised in  pages  i  to  96  provide  a 
reference  section  covering  all  es- 
sential study  required  by  the  drafts- 
man in  acquiring  a  mastery  of  sheet 
metal  pattern  cutting. 

ARRANGEMENT  OF  CONTENTS. 

Chapter  i.       Terms  and     Definitions — 15  pages. 

Chapter  II.     Drawing  Instruments  and  Materials — 13  pages. 

Chapter  III.  Linear  Drawing — 6  pages. 

Chapter  IV.    Geometrical  Problems — 35  pages. 

Chapter  V.     Principles  of  Pattern  Cutting — 25   pages. 

Cutting.     2.    Flaring   Work.     3.   Triangulation. 
Chapter  VI.    Pattern    Problems    (3    Sections)— 325    pages,      i.    Miter 

430  Pages,  Size  10x13  Inches. 
Heavily   Bound  in   Cloth. 

Price,  $5.00. 

SHEET  METAL  PUBLICATION  COMPANY 

Tribune  Building,  New  York 


IE  NEW  J-   J- 
METALWORKER 
PATTERN  BOOK 


Elbow  Patterns  for 
all  Forms  of  Pipe 

A  treatise  upon  the  elbow  pattern  explaining  the  most 
simple  and  accurate  methods  for  obtaining 
the  patterns  for  elbows  in  all  forms 
of  pipe  made  from  sheet  metal 

With  Useful  Mathematical  Rules  and  Tables 
By  F.  S.  KIDDER 


One  of  the  first  and  most  important  considerations  for  the 
sheet  metal  worker  is  to  be  possessed  of  a  method  for  securing  the 
patterns  for  elbows  in  the  least  possible  time  consistent  with  ac- 
curacy. To  meet  the  popular  demand  and  provide  a  means  by 
which  unnecessary  expenditure  of  time  and  labor  may  be  avoided, 
the  author  presents  here  a  method  for  laying  out  elbows  with 
accuracy  and  despatch, 

Without  Resort  to  Geometrical  Display. 

With  the  service  of  this  handbook,  the  mechanic  will  be  enabled 
to  quickly  produce  the  patterns  for  elbows  in  round  pipe  of  any 
size,  angle  or  number  of  pieces,  by  the  simple  employment  of  a  pair 
of  compasses  and  a  straightedge. 

Size  4l/2  x  &/2  inches  (for  the  pocket),  73  pages,  35  figures, 
cloth  bound. 

PRICE,  $1.00 

SHEET  METAL  PUBLICATION  COMPANY 

Tribune  Building,  New  York 


Sheet   Metal   Work 

A  Practical  Manual  for  Sheet  Metal  Workers,  Treating  Cornice  and 
Skylight  Work,  Metal  Roofing,  Pattern  Drafting,  Etc. 


BY  WILLIAM  NEUBECKER 


This  is  a  first  class  book  on  shop 
and  construction  work,  covering  all 
of  the  ordinary  practice  in  architec- 
tural and  general  sheet  metal  work. 
It  is  a  valuable  shop  reference  book, 
and  a  reliable  guide  for  mechanics 
who  are  aiming  for  a  mastery  of  the 
most  essential  problems  of  sheet  metal 
construction  and  pattern  cutting. 

The  General  Divisions  of  This  Vol- 
ume Are  as  Follows: 


Tools  and  Methods  of  Obtaining  Pattern 3-26 

Workshop   Problems    26-132 

Skylights    133-157 

Roofing   158-192 

Cornice  Work  193-262 

Index 263-267 

267  Pages;  358  Illustrations  (6l/2  x  9^4  inches);  Half  Morrocco 
Binding   Price,  $3.00 


SHEET  METAL  PUBLICATION  COMPANY 

Tribune  Building,  New  York 


THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 


AN  INITIAL  FINE  OF  25  CENTS 

WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN 
THIS  BOOK  ON  THE  DATE  DUE.  THE  PENALTY 
WILL  INCREASE  TO  SO  CENTS  ON  THE  FOURTH 
DAY  AND  TO  $I.OO  ON  THE  SEVENTH  DAY 
OVERDUE. 


LD  21-100m-8,'34 


.  /L 


12855 


